I'd like to get a new set of heads for my '73 L48 and I'd like your opinion.

Rebuilt the engine 5,000 miles ago, used the original block and added the following:

MSD Distributor, MSD 6A Ignition box, K&N air intake, Edelbrock Carb 1407, Edelbrock Intake 2101, Edelbrock cam 2102, Edelbrock timing chain/cover 7800, Hooker Headers, 2.5'' pipes with H balance pipe, Flow Master mufflers series 40.



The Edelbrock power package recommends 60759 performer heads w/ 70cc combustion chamber. However, after some research I think I'd be better off with the new Edelbrock E-Street 5089 w/ 64cc combustion chambers pushing engine into 9:5:1 compression. Which would you recommend? Would you recommend something else in the $1,500 price range per pair?

I'm thinking that should produce ~350 hp and ~400 ft/lbs, am I off?



Thanks for your help,
Steve

 

Take a look at Brodix IK180. You're going to replace the cam too? Nice looking car!

 

Rebuilt as in bored with new pistons ? Can't imagine someone not getting rid of the L/48s dished pistons and going to a flat top. Regardless of either type you want nothing bigger then a 64cc chamber. $1500.00 would buy afr 180. Or really the IK180 for less then $1100.00 would flow plenty enough air and well beyond that of your goal of power.

 

Check out the Dart SHP heads, they are a lot of head for the money.

http://www.summitracing.com/parts/DRT-127121/


Scott

 

Thanks redman76

No, I wasn't planning to replace the cam. Edelbrock uses the 2102 cam with the E-Street 5089 heads on crate engines claiming 330HP 409ft/lbs.

JEGs has the Brondix you mentioned for $1,177.99, not bad.

Brodix #158-1021004
SB-Chevy IK 180 Aluminum Cylinder Heads
• Intake Ports: 180cc
• Combustion Chambers: 64cc
• Max Lift: .525"
• 1.250" single springs (100 lbs closed/300 lbs open)


You think this will work better than the Edelbrock heads with my setup?

I'm looking for the most bang for my buck, all informed comments are welcomed.

Steve

 

I rebuilt it because the plastic tube running to the oil pressure gauge cracked and no one noticed it while it was being painted. At the time I didn't know much about engine building, as this was my first, and learned as I rebuilt it. I've taken pride in doing everything myself, but sometimes you don't make the most informed decisions being your first time. Thanks for the advice

 

Rebuilt as in bored with new pistons ? Can't imagine someone not getting rid of the L/48s dished pistons and going to a flat top. Regardless of either type you want nothing bigger then a 64cc chamber. $1500.00 would buy afr 180 what i would do if willing to spend that much. Or really the IK180 for less then $1100.00 would flow plenty enough air for your goal of power.

 

So, do you still have the dished pistons or not? A 64cc combustion chamber with a flatop piston and a cam that small will give you a lot of compression, maybe too much.


Scott

 

If you still have an L/48 cam they are pitifull. .390/410 lift with only 195 .050 intake duration. Get some use out of your new heads and replace it.

I forgot about the new dart SHP they just came out with. It to has more then enough flow for your goals. Just can't see $1200.00 plus for heads with your kind of goal in mind.

 

Scott,

Yes, still have the dished pistons. The only things I've added to the L48 is what is listed in the original post. Thanks

Little Mouse,

I have an edelbrock 2102 cam in it. Thanks

You guys are quick, appreciate it.

 

Scott, those Dart heads look pretty good, did some quick searches and turned up quite a few happy customers. Did a quick chat with a Summit tech and he recommended the Darts over the Brodix or Edelbrock.

 

If your budget is $1500 afr 180 Eliminators are the way to go. They come with beehive springs set up for your cam with 65cc chambers for a little over $1400.
The cam specs are going to hold you back with most any performace head you install.


Duration at 050 inch Lift 204 int./214 exh.



Advertised Duration 278 int./288 exh.



Valve Lift with Factory Rocker Arm Ratio 0.420 int./0.442 exh

 

63mako,

Would you recommend I go with the AFR 180 heads over the Dart heads mentioned by Scott? With my cam will it make a difference in performance? I don't plan to change out the cam at this point, engine is running well and I don't feel like pulling it out again.

I've had this car for 11 years now and plan to keep it for at least 20 more, should I buy the AFR 180 heads and change out the cam next time I rebuild it?

Should I keep the factory rocker arms & pushrods, or should I be replacing them as well?

Thanks,
Steve

 

I was going to say something about that cam and having it tore down this far now is the time to get rid of it. AFR will have best airflow go for it if you want to spend the money. They would have how should we say more breathing room lol for future mods should you decide more torque is in order with say a 383 some day. You could do better even with an inexpensive summit brand cam and lifter kit.

But your going to have to watch 63mako lol you will be spending another $1000.00 for hydraulic roller cam lifters and roller rockers. Your only after 350 hp. The darts and the brodix have enough airflow to support well over 400hp.


Look at it this way say you spend $1500 or less for modern heads that flow air great to .500 plus lift and beyond worlds better then your old factory heads ever did and now your basiclly going to waste that only lifting the valve 420/440.

20 yrs is a long time you could get the urge for a 383. in that case you could look at the afr as a better long term investment. Your next rebuild could get expensive so at that time may as well have a 383. You will get bored with the 350hp over time and go well 475 hp sounds great with my 383 then the afrs start coming into more play lol.

 

If you have the means, definitely go with the AFR heads 63 Mako mentioned. You will be hard-pressed to find anyone complaining about an AFR head's quality or performance. The Dart SHP, Edelbrock E-street, Brodix IK 180, are great deals for the money, if budget is an overriding concern; the AFR heads will cost a little more, but they are worth it if you can afford it.

I don't really have enough experience with this sort of thing to speak from experience, but I have heard several very knowledgeable people on this forum say that under-cammed engines tend to have poor throttle response. Would any experts out there like to elaborate for the OP's benefit? Is his present cam (Edelbrock 2102) really going to be a problem in this regard? It will really help if you post your differential ratio and transmission type and converter stall speed, if applicable.

Is that your engine in the photo you posted? I'm asking because that engine already appears to have some sort of aftermarket aluminum heads, along with aluminum water pump. Unless they are just painted up to look like aluminum (poser!!!! Just kidding......)

See ya,


Scott

 

If your running a flat tappet cam his is the type of lobe profile you want. Lazy ramps with low lift. Similar to a factory lobe design. Durable and unlikely to wipe a lobe. If you want to make the most of almost any aftermarket head you need more lift and faster ramp rates. That 278 advertised would be about 224 duration @ .050 in a roller designed lobe. Where many get in trouble is when they want the fast ramp and bigger lift and are only willing to pay for a flat tappet. Power cost money. If your upgrading to a great head and have it tore down far enough to install them why suffocate them with a cam that really limits their ability to move air? Yes, I would put a roller in it. Yes, I would expect 30-40 HP extra across the entire operating range of the engine. Yes it will cost $800 to $1000 to do. Yes that is cheap for that much power increase across the entire RPM range. A set of 1.6 roller rockers would help if you stick with the existing cam.

 

He won't have great compression but if i were him for the tiney amount a summit cam kit costs i would get rid of the 204 intake duration edelbrock go on up to 214. he is short both lift and duration. anyway using .420 lift like he has is cutting the new heads off at the knees. I think around $100.00 would put him in a summit cam lifters then a set of inexpensive 1.6 rockers and pushrods. $ 1000.00 roller setups can wait till the bug for more them 350hp hits.

www.summitracing.com SUM K-1103 $100.00 along with some 1.6 rockers.

 

Reluctantly.......... On a rebuild with 5000 miles on it, a set of AFR heads and properly matched roller cam that bug miight not bite for quite awhile. If a roller is not in the price range this is a pretty good choice with 1.6 rockers.
http://www.summitracing.com/parts/SUM-K1103/

 

how much is one of those bare bones lunati roller kits cost.

 

$600 plus thrust button and pushrods. If you buy a Summit cam and lifter set and decent 1.6 rockers you will be around $2-300 and you still might need pushrods. So for $3-400 extra you get noticable extra power throughout the RPM range, the warm and fuzzy feeling of more than likely not wiping a lobe or worrying about using the correct high zddp oil, and getting the most out of your new heads. It is a no brainer for me but there are a lot of guys that go the other way.
http://www.lunatipower.com/Product.aspx?id=2549&gid=312

I have a buddy that used one of these and has been running it a ciouple years with no problems.
http://www.summitracing.com/parts/HRS-CL111145-10/
(they are ground on a billet core)That gets the price down another $100 and even if the OP is running a TH400 with a stock convertor and 3.08 gears the corvettes with the 400 have a 2000RPM convertor stock.
It is no longer a $1000 upcharge to go roller.