[C2] Engine Rebuild Advice
Thread Starter
Instructor
Joined: Jul 2022
Posts: 165
Likes: 103
From: North Salt Lake, UT
I would rebuild to L79 specs and use the speed pro L2166NF pop up pistons with a set of double hump heads. They are pretty plentiful,, but the dates may not match up to engine dates but it will look correct. Howards or Elgin should have a GM 151 replacement cam unless you decide to controller cam if you have budget.
Anyone know a guy who has some solid 461/462 heads that I could snag without braking the bank?
Team Owner
Joined: Feb 2003
Posts: 54,139
Likes: 9,447
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
I'm inclined to go in this direction. Is there a laundry list of things that need to be done to convert my 300HP to the L79, 350HP spec? You mentioned getting the 461/462 heads (I'm working on that now), do the intake valves need to be 2.02? You mentioned a specific piston. Were the pistons different between these two engines? The last thing you mentioned was the cam. So no change to the crank, rods, lifters, valve springs, other?
Anyone know a guy who has some solid 461/462 heads that I could snag without braking the bank?
Anyone know a guy who has some solid 461/462 heads that I could snag without braking the bank?
Racer
Joined: Sep 2022
Posts: 255
Likes: 51
From: CALIFORNIA
St. Jude Donor '25
I'm inclined to go in this direction. Is there a laundry list of things that need to be done to convert my 300HP to the L79, 350HP spec? You mentioned getting the 461/462 heads (I'm working on that now), do the intake valves need to be 2.02? You mentioned a specific piston. Were the pistons different between these two engines? The last thing you mentioned was the cam. So no change to the crank, rods, lifters, valve springs, other?
Anyone know a guy who has some solid 461/462 heads that I could snag without braking the bank?
Anyone know a guy who has some solid 461/462 heads that I could snag without braking the bank?
Good luck.
Make sure if you reuse the rods to have them checked as they are prone to cracks at the mating surfaces.
Drifting
Joined: Dec 2015
Posts: 1,319
Likes: 221
From: Dalton, Ma
Since I just had an engine built last year....don't expect everyone is qualified to machine/build your engine. The guy who built made serious mistakes, and was anything but forthcoming on he mistakes.
If you find a good guy, ask his opinion on the single most important issue with a rebuild in today's world, wiping a new cam. He may suggest a hydraulic roller cam [$900] for reliability, if he suggests a non roller cam, make sure HE breaks in the engine and warranty's the cam without excuse. If YOU stare the engine and there is a failure, he will blame YOU for not breaking the engine in properly [and he might be correct] Maybe you can reuse the cam you already have [that is already broken in]
Keep the compression ratio down. Find correct 300 hp heads. You really don't come across as a guy who is jonesing for a L-79 and its negatives....
I don't agree with the hassle of adding a 5 speed...KISS,
If you find a good guy, ask his opinion on the single most important issue with a rebuild in today's world, wiping a new cam. He may suggest a hydraulic roller cam [$900] for reliability, if he suggests a non roller cam, make sure HE breaks in the engine and warranty's the cam without excuse. If YOU stare the engine and there is a failure, he will blame YOU for not breaking the engine in properly [and he might be correct] Maybe you can reuse the cam you already have [that is already broken in]
Keep the compression ratio down. Find correct 300 hp heads. You really don't come across as a guy who is jonesing for a L-79 and its negatives....
I don't agree with the hassle of adding a 5 speed...KISS,
Safety Car
Joined: Nov 2001
Posts: 4,424
Likes: 619
From: northern CA
Not to Highjack this thread, but ...
What compression numbers are folks getting when putting the TF Aluminum Heads (Camel Hump look a likes, 175 runner and 60 cc chambers) on an L79 motor with the orig domed pistons (e.g. replacing the stk '461's with their larger 64 cc chambers) ?? I read on someone's web site that the Dome on the Sealed Power L2166 forged pistons was -6.3 cc's.
I don't know how much the Domed Pistons reduce the Combustion Chamber and when i play with various calculators, I get 11.3: -to- 12:1 sort of numbers and i don't want to mess with that...
What compression numbers are folks getting when putting the TF Aluminum Heads (Camel Hump look a likes, 175 runner and 60 cc chambers) on an L79 motor with the orig domed pistons (e.g. replacing the stk '461's with their larger 64 cc chambers) ?? I read on someone's web site that the Dome on the Sealed Power L2166 forged pistons was -6.3 cc's.
I don't know how much the Domed Pistons reduce the Combustion Chamber and when i play with various calculators, I get 11.3: -to- 12:1 sort of numbers and i don't want to mess with that...
My 327 (.040) got the TF 175 heads. Using flat top pistons and .015 Fel Pro 1094 steel shim head gaskets the compression went up from 9.5 to 10.0
Factory stock connecting rods were also changed out during engine rebuild for SCAT cap screw style rods.
John
Last edited by mrg; Apr 12, 2024 at 06:45 PM.
Team Owner
Joined: Feb 2003
Posts: 54,139
Likes: 9,447
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Since I just had an engine built last year....don't expect everyone is qualified to machine/build your engine. The guy who built made serious mistakes, and was anything but forthcoming on he mistakes.
If you find a good guy, ask his opinion on the single most important issue with a rebuild in today's world, wiping a new cam. He may suggest a hydraulic roller cam [$900] for reliability, if he suggests a non roller cam, make sure HE breaks in the engine and warranty's the cam without excuse. If YOU stare the engine and there is a failure, he will blame YOU for not breaking the engine in properly [and he might be correct] Maybe you can reuse the cam you already have [that is already broken in]
Keep the compression ratio down. Find correct 300 hp heads. You really don't come across as a guy who is jonesing for a L-79 and its negatives....
I don't agree with the hassle of adding a 5 speed...KISS,
If you find a good guy, ask his opinion on the single most important issue with a rebuild in today's world, wiping a new cam. He may suggest a hydraulic roller cam [$900] for reliability, if he suggests a non roller cam, make sure HE breaks in the engine and warranty's the cam without excuse. If YOU stare the engine and there is a failure, he will blame YOU for not breaking the engine in properly [and he might be correct] Maybe you can reuse the cam you already have [that is already broken in]
Keep the compression ratio down. Find correct 300 hp heads. You really don't come across as a guy who is jonesing for a L-79 and its negatives....
I don't agree with the hassle of adding a 5 speed...KISS,
if his end goal is drive on the highway at 80+ a overdrive will save his engine in the long run
Thread Starter
Instructor
Joined: Jul 2022
Posts: 165
Likes: 103
From: North Salt Lake, UT
461/462 heads are everywhere for sale. don't pay extra for the 2.02 valves. just have the machine shop make them for you. L79 had pop up pistons. the crank was heat treated and drilled and taped for the balancer bolt. with that said L79 used a 8' balancer unlike the 6" 300 hp one.
Adrian's notes page/laundry list:
New cam - Not sure on whether to go stock or roller cam. I'll check with my machine guy. KarKrafter - your input on that is duly noted.
New lifters - Jimnan mentioned hardened face lifters as expensive, but cheap insurance for cam failure. I assume the concern is with stock cams, not roller cams. Maybe if you spend the money on the roller cam, you don't need to spend as much on the lifters.
New pistons - Lots of recommendations on flat, some on domed. Is there an octane concern for high compression domed cylinders? I want as much power as I can get, but don't want to have to buy jet fuel!
New heads - I had been considering getting double humps and now I'm 100% on board. This will likely mean new valves and springs as well. Any thoughts on whether I should have the shop add valve seats? Waste?
New balancer - 8" instead of 6".
Check the rods, replace if needed
I assume new push rods goes without saying... but I just said it.
Replace water pump - I didn't mention it in this thread, but I think Nowhere Man caught in another post of mine that the water pump was a little rusty and likely needed replacing. Thanks NWM!
New Carb - Again, I didn't mention here, but my carb is a non-stock Holley 600 cfm unit and I have read that it can chock the L79, so I will look at a 750 cfm unit.
I've already sourced the new aluminum script valve covers - they're hanging on my wall as inspiration!
Thanks again for all your input and helping me keep things straight!
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Team Owner
Joined: Feb 2003
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From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
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yes the balancer was eight inches. with pop up stock pistons and the proper head gasket thickness and stock style tune you will be able to run 93 pump gas. with any used heads the machine shop/ engine builder with match the valve springs to the cam selected. if your having the heads machined from 1.94 to 2.02 valves your need new intake valves. I would not use harden seats unless you're pulling a trailer up a mountain. I would put the 66-67 style 327 rods if you don't have them already. cheap insurances. if you're going to make a L79 with the correct intake you're need a water pump with a by-pass fitting on top. the stock carb for the base 300 and L79 was only a 585 CFM . I am a huge fan of using a oem carb even if you get a 70's service dated carb. the reason so is so you don't have to mickey mouse anything.
I will stay out of the cam type discussion but if you choose anything but a oem L79 grind cam then yow wont have an L79
I will stay out of the cam type discussion but if you choose anything but a oem L79 grind cam then yow wont have an L79
Drifting
Joined: Jul 2014
Posts: 1,556
Likes: 791
From: Massachusetts
Hello Forum Friends
I have been working through a 1966 frame off restoration with my dad and have gotten to the point where we are going through the numbers matching, 300HP, 327 engine (3858174). When we got the car, the engine was leaking from the rear main seal, from the oil pan, the oil filter, the heads, the valve covers… Pretty much if there was a place for this thing to leak, it would. We pulled the engine from the car and started dismantling it to see what was needed. We discovered that someone had been in the engine previously with heavy instrument scoring in the cylinders and non-stock pistons.
We took the engine in to a professional shop for inspection and cleaning. They confirmed that the engine had been apart in the past and that the cylinders would need to be bored 30 thousanths over. They verified that there are no cracks in the block or the heads (non-stock 1971 [3973487] Corvette heads) and I should be able to pick up these items soon for painting ahead of reassembly. While the engine shop has the engine apart, they have prepped me for an upcoming conversation to discuss what I want to put back in this thing. Obviously the heads and cylinders are not stock and the bore is not correct for the car. So I’m looking for recommendations from the forum on what could/should be done to this engine.
I’m sure many of you will ask what my goals are for this car. While it is a numbers matching car, we had to scrap the frame and other parts due to high rust deterioration. This will never be an NCRS garage queen. We want the car and engine to look stock, but only to the non-NCRS crown. We want it to be able to drive comfortably at freeway speeds -70-80 mph here in Utah. We also want the car to be fun to drive around town from stop light to stop light. Should I be looking at new crank/connecting rods, new cam, new lifters? What’s going to give me good power while keeping the notorious reliability of the 327 SBC? Since I want this to look relatively stock, I’m not interested in aluminum heads or fancy intakes or anything like that.
I’m a MAJOR rookie on all of this, so your thoughts and opinions are appreciated! I’m open to reconsidering my ‘goals’ if there is something you are passionate about that I should be considering.
I have been working through a 1966 frame off restoration with my dad and have gotten to the point where we are going through the numbers matching, 300HP, 327 engine (3858174). When we got the car, the engine was leaking from the rear main seal, from the oil pan, the oil filter, the heads, the valve covers… Pretty much if there was a place for this thing to leak, it would. We pulled the engine from the car and started dismantling it to see what was needed. We discovered that someone had been in the engine previously with heavy instrument scoring in the cylinders and non-stock pistons.
We took the engine in to a professional shop for inspection and cleaning. They confirmed that the engine had been apart in the past and that the cylinders would need to be bored 30 thousanths over. They verified that there are no cracks in the block or the heads (non-stock 1971 [3973487] Corvette heads) and I should be able to pick up these items soon for painting ahead of reassembly. While the engine shop has the engine apart, they have prepped me for an upcoming conversation to discuss what I want to put back in this thing. Obviously the heads and cylinders are not stock and the bore is not correct for the car. So I’m looking for recommendations from the forum on what could/should be done to this engine.
I’m sure many of you will ask what my goals are for this car. While it is a numbers matching car, we had to scrap the frame and other parts due to high rust deterioration. This will never be an NCRS garage queen. We want the car and engine to look stock, but only to the non-NCRS crown. We want it to be able to drive comfortably at freeway speeds -70-80 mph here in Utah. We also want the car to be fun to drive around town from stop light to stop light. Should I be looking at new crank/connecting rods, new cam, new lifters? What’s going to give me good power while keeping the notorious reliability of the 327 SBC? Since I want this to look relatively stock, I’m not interested in aluminum heads or fancy intakes or anything like that.
I’m a MAJOR rookie on all of this, so your thoughts and opinions are appreciated! I’m open to reconsidering my ‘goals’ if there is something you are passionate about that I should be considering.
1) Absolutely, positively, ensure that the block is not decked and the original matching numbers pad is preserved. Preserving the matching numbers block will have a big effect on the resale value of the car (about $10K difference). Even if you personally don't think preserving the pad is important, it may make a biig difference to a potential future owner.
2) The replacement frame and .030" overbore have zero effect on NCRS judging points.
3) Do not spend any money on the existing 3973487 heads or even numbers-matching original heads. Buy the Trick Flow DHC aluminum heads and paint them Chevy orange. Their external appearance will fool everyone except a very experienced NCRS judge, and their internal design greatly exceeds the performance of even ported stock heads. The cost is comparable to a set of fully reworked stock heads (stock heads with stainless valves, threaded studs, hardened valve seats, positive valve seals, pushrod guides, and pocket porting). Just buy the Trick Flow DHC heads and be done with it. Note that the 3973487 heads have mounting holes for accessories and are very obviously wrong for a '66. The '66 heads did not have these mounting holes in the front face of the heads. And the Trick Flow DHC heads don't have them either (if you purchase the correct version).
4) Do not re-use the stock rods. Buy a set of Scat Pro-stock or Eagle SIR budget performance rods. These are far superior to the stock rods, at a cost that is not much more than having the stock rods checked and re-conditioned.
5) For an inexpensive boost in torque and horsepower, do as DZAUTO has suggested and stroke the engine to 350 CID. All you need to do is have the mains journals turned down on a 350 crank. This is a very popular upgrade to a 327.
6) With the Trick Flow aluminum heads the engine will tolerate compression of 10.5 to 11.0 on 93 octane pump gas. With the 350 stroke of 3.48", flat-top pistons, and the 60 cc Trick Flow heads you should be in the right range with a suitable thickness head gasket.
7) From a performance perspective, the L79 cam flat tappet cam is perhaps the best all-around street cam that GM ever made for the small block. The only issue with using this cam is the possibility of wiped can lobes during break-in. A roller cam with similar duration and lobe separation angle (LSA) costs more but eliminates the risk of a wiped lobe. The roller cam can also have more lift while maintaining the duration and LSA of the L79 cam.
8) For highway driving at 70-80 mph, you will absolutely LOVE having a 5th gear overdrive of around 0.68. And, the 5-speed will come with a lower 1st gear ratio compared to a Muncie, which will give you a stronger launch from a standing start. If you don't mind the cost (about $4500), the Tremec TKX from Silver Sport Transmissions is an excellent choice. The 600 ft-lb torque rating of the TKX is overkill for a L79 clone, but otherwise it is a wonderful upgrade. For a typical small block, a Tremec T5 can be installed for much lower cost, as I have described in another thread on T5 5-speed conversions. Either way, the overdrive 5th gear makes a huge difference for driving at 70-80 mph. You will not be sorry for making the conversion to a 5-speed.
Thread Starter
Instructor
Joined: Jul 2022
Posts: 165
Likes: 103
From: North Salt Lake, UT
I have read through this thread on April 12, after several responses have already been made. I strongly disagree with the view that it is okay to deck the block (removing the matching numbers on the pad). On the other hand, I agree with some of the other advice. Following are my thoughts:
1) Absolutely, positively, ensure that the block is not decked and the original matching numbers pad is preserved. Preserving the matching numbers block will have a big effect on the resale value of the car (about $10K difference). Even if you personally don't think preserving the pad is important, it may make a biig difference to a potential future owner.
2) The replacement frame and .030" overbore have zero effect on NCRS judging points.
3) Do not spend any money on the existing 3973487 heads or even numbers-matching original heads. Buy the Trick Flow DHC aluminum heads and paint them Chevy orange. Their external appearance will fool everyone except a very experienced NCRS judge, and their internal design greatly exceeds the performance of even ported stock heads. The cost is comparable to a set of fully reworked stock heads (stock heads with stainless valves, threaded studs, hardened valve seats, positive valve seals, pushrod guides, and pocket porting). Just buy the Trick Flow DHC heads and be done with it. Note that the 3973487 heads have mounting holes for accessories and are very obviously wrong for a '66. The '66 heads did not have these mounting holes in the front face of the heads. And the Trick Flow DHC heads don't have them either (if you purchase the correct version).
4) Do not re-use the stock rods. Buy a set of Scat Pro-stock or Eagle SIR budget performance rods. These are far superior to the stock rods, at a cost that is not much more than having the stock rods checked and re-conditioned.
5) For an inexpensive boost in torque and horsepower, do as DZAUTO has suggested and stroke the engine to 350 CID. All you need to do is have the mains journals turned down on a 350 crank. This is a very popular upgrade to a 327.
6) With the Trick Flow aluminum heads the engine will tolerate compression of 10.5 to 11.0 on 93 octane pump gas. With the 350 stroke of 3.48", flat-top pistons, and the 60 cc Trick Flow heads you should be in the right range with a suitable thickness head gasket.
7) From a performance perspective, the L79 cam flat tappet cam is perhaps the best all-around street cam that GM ever made for the small block. The only issue with using this cam is the possibility of wiped can lobes during break-in. A roller cam with similar duration and lobe separation angle (LSA) costs more but eliminates the risk of a wiped lobe. The roller cam can also have more lift while maintaining the duration and LSA of the L79 cam.
8) For highway driving at 70-80 mph, you will absolutely LOVE having a 5th gear overdrive of around 0.68. And, the 5-speed will come with a lower 1st gear ratio compared to a Muncie, which will give you a stronger launch from a standing start. If you don't mind the cost (about $4500), the Tremec TKX from Silver Sport Transmissions is an excellent choice. The 600 ft-lb torque rating of the TKX is overkill for a L79 clone, but otherwise it is a wonderful upgrade. For a typical small block, a Tremec T5 can be installed for much lower cost, as I have described in another thread on T5 5-speed conversions. Either way, the overdrive 5th gear makes a huge difference for driving at 70-80 mph. You will not be sorry for making the conversion to a 5-speed.
1) Absolutely, positively, ensure that the block is not decked and the original matching numbers pad is preserved. Preserving the matching numbers block will have a big effect on the resale value of the car (about $10K difference). Even if you personally don't think preserving the pad is important, it may make a biig difference to a potential future owner.
2) The replacement frame and .030" overbore have zero effect on NCRS judging points.
3) Do not spend any money on the existing 3973487 heads or even numbers-matching original heads. Buy the Trick Flow DHC aluminum heads and paint them Chevy orange. Their external appearance will fool everyone except a very experienced NCRS judge, and their internal design greatly exceeds the performance of even ported stock heads. The cost is comparable to a set of fully reworked stock heads (stock heads with stainless valves, threaded studs, hardened valve seats, positive valve seals, pushrod guides, and pocket porting). Just buy the Trick Flow DHC heads and be done with it. Note that the 3973487 heads have mounting holes for accessories and are very obviously wrong for a '66. The '66 heads did not have these mounting holes in the front face of the heads. And the Trick Flow DHC heads don't have them either (if you purchase the correct version).
4) Do not re-use the stock rods. Buy a set of Scat Pro-stock or Eagle SIR budget performance rods. These are far superior to the stock rods, at a cost that is not much more than having the stock rods checked and re-conditioned.
5) For an inexpensive boost in torque and horsepower, do as DZAUTO has suggested and stroke the engine to 350 CID. All you need to do is have the mains journals turned down on a 350 crank. This is a very popular upgrade to a 327.
6) With the Trick Flow aluminum heads the engine will tolerate compression of 10.5 to 11.0 on 93 octane pump gas. With the 350 stroke of 3.48", flat-top pistons, and the 60 cc Trick Flow heads you should be in the right range with a suitable thickness head gasket.
7) From a performance perspective, the L79 cam flat tappet cam is perhaps the best all-around street cam that GM ever made for the small block. The only issue with using this cam is the possibility of wiped can lobes during break-in. A roller cam with similar duration and lobe separation angle (LSA) costs more but eliminates the risk of a wiped lobe. The roller cam can also have more lift while maintaining the duration and LSA of the L79 cam.
8) For highway driving at 70-80 mph, you will absolutely LOVE having a 5th gear overdrive of around 0.68. And, the 5-speed will come with a lower 1st gear ratio compared to a Muncie, which will give you a stronger launch from a standing start. If you don't mind the cost (about $4500), the Tremec TKX from Silver Sport Transmissions is an excellent choice. The 600 ft-lb torque rating of the TKX is overkill for a L79 clone, but otherwise it is a wonderful upgrade. For a typical small block, a Tremec T5 can be installed for much lower cost, as I have described in another thread on T5 5-speed conversions. Either way, the overdrive 5th gear makes a huge difference for driving at 70-80 mph. You will not be sorry for making the conversion to a 5-speed.
Pro
Joined: Feb 2015
Posts: 638
Likes: 133
From: Omaha NE
I think Speedway has their own design and are not the same Trick Flow heads. (I may be wrong). BUT USE A Hydraulic ROLLER CAM!!!!
Do your research and you will find that flat tappet cams are failing at a high rate. I am doing a rebuild now after 1500 miles... Some say it's the cam, others the say lifters, and even the type of oil. Yes, it will be expensive! -- Not as expensive as doing it twice!
I am using Howards cams, great people to talk to and better customer service!
I am doing exactly what the same thing right now on my engine. I would do everything Joe posted. Since it is the numbers matching block, I would be very careful not to go down the rabbit hole of more hp, bigger cam, and stroking it.
You'll get more hp AND reliability than you will need with a very mild upgrade.
I would rather be driving mine not rebuilding it...
Do your research and you will find that flat tappet cams are failing at a high rate. I am doing a rebuild now after 1500 miles... Some say it's the cam, others the say lifters, and even the type of oil. Yes, it will be expensive! -- Not as expensive as doing it twice!
I am using Howards cams, great people to talk to and better customer service!
I am doing exactly what the same thing right now on my engine. I would do everything Joe posted. Since it is the numbers matching block, I would be very careful not to go down the rabbit hole of more hp, bigger cam, and stroking it.
You'll get more hp AND reliability than you will need with a very mild upgrade.
I would rather be driving mine not rebuilding it...
Last edited by 61corv; Apr 13, 2024 at 05:29 AM.
Drifting
Joined: Dec 2015
Posts: 1,319
Likes: 221
From: Dalton, Ma
L79's were great engines but they weren't for every application.
Le Mans Master
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From: Richardson Texas
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From: US-PNW
Team Owner
Joined: Feb 2003
Posts: 54,139
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From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
I'll say this again out of the 5 classic cars my dad and I own. One base 300, L79 an L76, L36 and my Chevelle 396/360. I would pick the L79 if I needed one to drive every day. The other ones have there strong points for sure but the L79 is great all around and plenty of power
Drifting
Joined: Jul 2014
Posts: 1,556
Likes: 791
From: Massachusetts
For your build, only the flows for up to 0.5" are of interest (L79 cam lift is .447"). If you compare the flows for lifts up to 0.5", you will see that the Trick Flow heads out-perform the Speedway heads by a significant margin. The performance margin over stock L79 heads is even larger.
BTW, there are four versions of the Trick Flow DHC heads that all flow the same, but have other important differences. There are two different external appearances, depending whether you are trying to match the external appearance of a '66 head (no mounting holes for accessories on '66 heads, mounting holes for later heads). There are also two different spring sets (one for flat tappet cams and one for roller cams).
So, you will want to decide on flat-tappet or roller cam before you order the Trick Flow heads. And, you want to be sure to get the version with no holes for mounting accessories.
Burning Brakes
Joined: Mar 2012
Posts: 987
Likes: 171
From: Kingwood Texas
L79 does not use the 30 30 solid lifter cam. L79 lifters are hydraulic.
I'm not an expert but the OP would have an additional cost of the correct heads and intake. And if memory serves..11:1 compression is a pain. 30-30 cam is a solid lifter cam which requires maintenance that an unsophisticated owner may find a challenge. The idle may not have been everyone's cup of tea, like side pipes aren't everyone's cup of tea. Guessing it would move the torque curve up 1000 rpm over the 300 hp mill which is not as drive-able at lower speeds, around town. Just trying to give the OP some insights he may not have.
L79's were great engines but they weren't for every application.
L79's were great engines but they weren't for every application.