You can put TPI on your stock bottom end/long block then add headers or C4 TPI manifolds and dual exhaust later. TPI will really wake up a stock later C3. If interested I have a little more info on installing TPI that I have posted before. Let me know and I will post it tomorrow.

 

I appreciate all the excellent recommendations all of you have made. I will be doing the work myself so there won't be any labor cost to speak of. The engine runs very good, has good oil pressure and doesn't burn any oil. This is the reason I just want to do mods without tearing it down at the moment. I like the idea of the L-82 cam with the lift and duration that was mentioned. a good intake and carb setup and headers. This will get me close to where I will eventially end up. A set of performance heads would be the next alternative but the budget eliminates them for the time being. I will print this info and analyze it along with going to the different vendors for packages with the guidelines you guys have given me. I built the 350 in my 89 Silverado a couple years ago. Bored it 30 and installed an RV grind cam, and true duals with glass packs. It pulls like a pack mule and sounds great. It is a truck and that is what I use it for so it does exactly what I want it to; but the Vette needs to run like the muscle car it is supposed to be. Thanks again for all your help!

 

Bernie:
if you don't want to spend all that $$$ on heads at this time, but have 'some' of the scheckels saved-up, are doing your own work, don't do too-much highway driving, and/or don't mind poor gas mileage, see if anybody makes 4.10 gears for your '63-'79 series-3 carrier:
you're already running 3.55s, so it won't be THAT much deeper gearing, your 'future' better-breathing heads will appreciate it, and at 6000 RPM, you'll top-out at around 110, but you'll get there MUCH quicker!!!!!

 

I tried to post a reply earlier and it didn't work so will try again. I want to thank everyone for their suggestions. They were definately in the direction I want to go. I appreciate the lift and duration numbers for the cam. That definately sounds where I want to be. Since the engin runs good, has good oil pressure and doesn't burn any oil I decided to wait to do the bottom; but when that time comes the 383 stroker sounds like a possibility. I built my 89 Silverado 350 a few years ago; bored it 30 installed new flat tops, an RV grind cam and true duals with glass packs. It pulls like a pack mule, sounds great and with the tall rear end and od tranny it will cruise all day with the spedo buried. But Corvettes are muscle cars and I want this one to be what it is supposed to be so the mods you guys have suggested will put me on the way to getting there. Thanks for the info; i have printed it and will use it to create the car I want to drive.

 

Verified dyno results (check Trick Flow Specialties web site) TFS 23 small block chevy heads alone add 57 hp over stock......add your cam & headers, etc., & go up from there...

 

Mark. I would appreciate a post on the TPI install. Would definately like to consider that possibility. On the 4:10 gear issue; I don't intend on drag racing the car. 3:55's are as big a gear as I want and coupled to an overdrive tranny or 5/6 speed it will have the taller legs I want to get down the interstate and still have decent fuel mileage. I used to drag race years ago but now enjoy touring and watching others race. Just want a car that will get me there fast and run with the current "muscle" cars Detroit and others are building. Thanks again for the info. My double thanks printed earlier; didn't realize the thread split into more pages!

 

C#Stroker, looks like those heads are a "must have" when the budget will allow. I have spent so much on it this year I need to start spreading the dollars out a little. They are more easily absorbed that way. Thanks again fore everything!

 

Here's what I did on my 79 L48 while I had VanSteel installing the Bowtie 2004r with an 1800 stall converter:
Comp Cams magnum 270H cam (don't know if one I replaced was stock)
Dynomax Ceramic coat headers
MAD 2.5 inch chambered exhaust.

I had true duals through manifolds before the switch.

best 1/4 mile time on that setup was 15.0. According to the HP from ET calculator on smokemup.com that should be around 250-260 HP. Stock is 195.

The intake is still stock and so are the heads. From previous posts, most members agree those are now the choking points. Might need a little more compression too.
But I have other plans.. buhahahahaha!

 

Since I already have an L-82, the cam is OK.
How are the L-82 heads (Except for the CR).
Could they be milled to up the CR and cleaned up for some HP? Is that a good idea?
Are the heads worth keeping?

 

I think the biggest bang is the gears! Your going to 3.55s, that's a excellent choice. I had a 74 L-48 with 70 350 194 heads, LT-1 solid lifter cam ( would recommend the L-82 cam ), headers, carb, it wouldn't run outta the hole to whip a beat Bettle The 308 gears & tall L-60s really sucked. When I tried a couple bracket races ( mostly to check ETs ) it would bog outta the hole till 3500rpm when it would come on the cam. At a 15 second dial in :o , I had a huge start to every car I ran but at 40mph two things happened! They pulled up beside me & my motor would start pulling to the surprise of a lot of BB cars that couldn't get away to the tune of 107mph thru the traps I'm guess it woulda been an honest low14 to high 13 second car with .355-.370 gears. Sorry to drag on , but your gear choice with some other simple engine mods ( cam, carb, intake,timing, headers? & heads?) will do the trick

 

Glensgages,

I forgot to put my 2700 TC in my sig, but it's there now. My 79 seems to run pretty good for what it's got. I'm looking at either the vortec head package from Pace Performance for $795.00 or a few other heads from other vendors. I would like to get near the 12s....Perhaps the original poster can utilize the Pace Performance option...

 

You have a unit
First you have to determine whether you want mass air flow or speed density. The C3 is more conducive to speed-density due to space issues. Mass-air flow is easier to make engine changes without PROM changes. If you are technically proficient enough to make a Camaro harness work they can be bought for $100 or less. I have been told that you can also use a Cavailier harness with a little work, it uses the same ECM. Aftermarket harnesses range from about $300 for Painless to $500 for Howell to $700 for Street and Performance. Howell makes a great harness, but for a Tuned Port they do not make one that will control the converter lockup on a 200R4/700R4/4L60 transmission. If you are running a manual or non-overdrive-automatic transmission I highly recommend them. I have heard great things about Street and Performance harness, but do not have first hand experience with them. I also have a Fuel Injection Specialties (FIS) harness and it is OK. The ECM can be had used for $10-50. A good external fuel pump will cost at least $100. I use an 88 Ford Truck external pump, $114 from CarQuest, made in Texas by Airtech. If you have a 78-82 you can use your fuel tank with an 82 sending unit and a TPI pump. An aftermarket PROM with VATS and Emissions codes removed will be $100-200 depending on source and complexity. You will have to add an oxygen sensor to your exhaust, $20 for the sensor, $5 for the weld-in bung, and say $25 for an exhaust shop to weld it in if you can’t. Some harnesses use VSS and some do not. An auxiliary VSS sensor is around $75. To install a TPI I say figure at least $800 plus the TPI unit and whatever repairs are necessary to bring it up to useable status. I have TPI/700R4 in my 69 Corvette (Howell harness) and an 83 Pickup (FIS harness) and I love it. Starts good, great torque, good fuel mileage, easy to swap onto stock engines (although both of mine are out of 90/91 ‘Vettes).

Differences in years
All Corvette TPI intake manifolds work with the older (through 86) iron heads and the factory aluminum heads through 91. F-body TPI intakes use the upright center bolts on 87-92 and thus fit all 87-95 iron heads (non LT1). Either can be swapped to fit the other with some drilling. F-body has the fuel lines come out on the drivers side and has a central port for EGR. Corvette has fuel lines that come out on the passenger side and has an external port for EGR. Corvette fuel rails fit F-body intakes and vise-versa. The runners are all the same through the years, but the LH runner has a hole for a 9th injector in the 85-88 runners. This can be plugged off if you get a nice LH runner and don’t want the 9th injector or decide to run speed-density. The plenums all physically interchange, but 90-92 have an extra vacuum port for the MAP sensor used with the speed-density computers and wiring. 89 is an odd year, it is mass-air flow but without the 9th injector. 89 up throttle bodies can be used on all years, but a 85-88 throttle body requires a ½” hole be drilled in the front of a 89-92 Plenum for idle air. 89-92 Throttle bodies have a bit more desirable cable attachment. The cable attaches around a circular linkage which has a smoother actuation than the straight linkage on the 85-88. The Corvettes have an aluminum plenum extension over the distributor, the F-body extensions are plastic. The Corvettes use an HEI coil-in-cap distributor for 85-91 (Delco 1103680). 85-86 F-body also used a big-cap distributor. 87-92 F-Body used a small cap distributor with an external coil (Delco 1103479). This same distributor is used in the 87-95 5.0/5.7/7.4 TBI injected trucks. The F-body intake gets it's exhaust for EGR from the center passages in the heads like most SB Chevys. A Corvette intake gets it's EGR exhaust from the RH exhaust manifold/header through a flex-tube to an opening near the distributor-no center passages in the intake. If you are required to keep EGR and you have a Corvette intake, I recommend geting the C4 exhaust manifolds. They are like mini-headers, and have a 2 1/2" outlet. I have them on my 69 and like them.

As far as a throttle cable to use, on my Vette, I used a TPI Corvette cable, 1990 I think (about $20 new GM) but you have to cut the end off inside the car and use a hood-release-cable end (Corvette Central 342138 "cable stop") to get it the correct cable length (the housing is OK). You must use a cable from the type car your throttle body came from if you want to have a chance of not cutting it. Again, 85-88 use a straight pull, while 89-92 have a circular attachment for more smooth actuation and so the inner cable is longer. On my 83 truck I used a TPI F-Body cable and it was OK, but I had to coil it up into a loop in the engine compartment because the housing was so long. I also TPI'd a 72 Chevy truck and used a 90 350 TBI truck cable for it. It was 1/2" short outside if anything, but I was pretty pleased with it all told-I didn't have to shorten it. In a Vette it might be about right. In all vehicles I've done you need a die grinder to square the firewall hole off a bit. All vehicles I've done used the late throttle-body.

Why to get it
If all you want is around 300 hp there is no reason to spend a pile of money on a crate motor. The basic $1200 4-bolt Goodwrench 350 with an aluminum intake and a Holley will put out power in that neighborhood. Chevy High Performance (I think) did a series of articles with one of those a few years back and with decent exhaust should get you in that range.

I would look into a TPI. They start immediately in winter, have great vacuum, and will get great mileage. I can open the headlights and the wiper door at the same time with no hesitation at all-solid wooomp. With 3.70 gears (and a 700R4 overdrive) I get 18mpg city and 22+ highway. With 3.55 or 3.36 it would be even better. You can probably find a used Corvette TPI engine for $1000 and with an $800 harness/computer/fuel pump you would be set. On a 78-82 you can use the stock fuel tank with an 82 sending unit and TPI pump and be in better shape than 68-77 with an external pump. With the Vette TPI you would have aluminum heads that would remove weight. Even with an F-body iron-head TPI 350 it will be less weight than a stock intake. It will bolt up to everything in your car, use stock accessories, use your transmission, and the visual appeal is awesome. Don't be afraid of fuel injection, it really works.

As far as websites see:
www.corvettefaq.com for conversions or more TPI info at www.fuelinjection.com

 

 

The TPI Engine swap sounds like an awesome package that would perform like I want. Very good power, Very good economy and very good reliability. I'm torn between spending less money with add-ons to get better performance and saving for the TPI conversion. This is something that must be decided after Christmas. Either way I have the best information available which ever way I elect to go. Again thanks for everyone's input; it is appreciated and will be used to make my 79 the performer it should have been! This also proves how much good this forum does for those who really care about their cars and are willing to offer their expertise to help others. I hope that I am able to help others just as I have received it from all of you!

 

If your looking at aftermarket heads, look into Trick Flow 23* heads with the dual valve springs. They flow just a tad behind AFR's at almost twice the price. I think Summit is getting about $1100-$1200 a set. Another thing that worked for my Trans Am on the street was to install a set of 1.6:1 rockers in place of 1.5:1 that were stock. The increased lift did wonders to wake up the engine. Tpi will improve torque and fuel mileage. It probably won't add much horsepower, but remember people are impressed by high horse power numbers, but torque is what gets your car moving.

 

this is my upgrade that i will tie to a 700r4 3.08 rear and steeroids. i pick up engine tomorrow and post as i go

http://forums.corvetteforum.com/showthread.php?t=959450