Hey all,
Time to upgrade my 77 L48 auto, and thinking that headers/heads/cam is the way to go. Can anyone offer any advice on what combination of the 3 will give me some decent results? I have heard good things about the Dynomax headers, but what heads and camshaft should I buy? I'm not looking for anything too wild, but I'd like to try and get into the 250-300 hp range.

Any suggestions?
Thanks!

 

The Edelbrock Performer RPM package (heads, cam, and intake) will do a good job delivering the performace you are looking for.

 

No problem. Ex. is first. See Why Exhaust is problem for HP on 75-81,
which many refer to as my Exhaust topic. http://www.corvettefaq.com/c3/ganeyexhaust.htm

If you have that many miles on the engine, you should rebuild. Comp Cams 260H w/ good ex. will do it. Go w/ an Al. intake like Performer 2101 or Weiand Action+. Many good heads are available. Dynomax coated headers fit great & flow much better than is commonly known.

 

I would listen to Ganey...He knows his stuff.....Dont forget 2.5 exhaust and H or x pipe and good mufflers.......I have flowmaster 40's and love them...by the way I am running 041 64cc iron heads and they have worked out great

 

Ganey

I have a question... Would it be worth it for me to install a set of headers on my stock 1978 L82? I have a 3:70 rear and I was thinking about doing some bolt on's to get me some more seat of that paints power.

 

300 HP should be very easy to achieve. I am thinking that you may not have to touch the heads. Maybe at the most just a port job and a 3-angle valve job. Maybe someone else will put in there 2 cents.

- A cam with 212 (or less) of intake duration @ 0.05 lift. Remember to pick a cam that favors the exhaust side.
- Dual Plane intake (Edelbrock Performer Air Gap or EPS). It doesn't sound like you need the RPM.
- Headers with Flowmasters.

The Edelbrock Performer package can get you there with a very mild Performer cam (204/214 duration, 0.420/0.442 Lift)

 

Would it be true that if he had an L82 that the cam in that would do a great job with he new heads and intake?

 

SLICKMAN

Yes, headers will help. See the Exhaust topic.


Zach

That Performer cam is not enough for a 350 Corvette. One does not always need more ex. than intake duration.

 

Hedman Elite thermal coated headers-- $260
Edelbrock Performer intake-- $125
Comp Cams 260H or 268H kit-- $160
Trick Flow 64cc combustion chamber heads-- I believe a place in Dallas had them for $800, Summit has them for $1,300
--OR--
AFR 190's, 68cc combustion chambers--$1,250 from AFR, I plan on getting the 195's soon.
A true dual exhaust with a H or X pipe and free-flow mufflers would be a great addition to this package and the headers.

Feel free to e-mail me or post more here, I've researched forever on these topics before I started my engine build. Good Luck :cheers:

 

Do you need to pass smog still?
I had a Crane Powermax 272, .454/.489, 216/228@.050 in a stock L48 with Performer manifold and it was strong. It's also smog legal. If you don't need EGR, the Vortec heads are inexpensive and flow well, and there is a Performer intake for these. You may need a lower lift cam than the 272, as I think there is a recommended safe maximum lift with the Vortecs. The other heads mentioned are great but a lot more money. The Performer RPM cam is way too radical for your setup...had this in a 383 and it was still very lopey with low vacuum.

 

Hey Ganey- Ihave 2" true duals into stock vette mufflers, what do you think my h.p. and 1/4 mile results would be if I went to 2 1/2 and two flowmasters?

Thanks Spoke-

 

You've got the right idea and those are exactly the items that will give you the most power for your money. I'm assuming that you've already read Ganey's info on exhaust and that you realize that, though valuable as headers are, they aren't the only part of your exhaust that can be improved. (Good to see ya again Ganey!) Also consider a higher stall converter though. Besides providing a nice improvement in accelleration on it's own, it'll give much better drivability with the changes that you have in mind. Your cam and head selection should consider how you intend to use the car, now and in the future, and how much drivability you're willing to give up in exchange for more power.

Generally, bigger heads and cam will make more power but for a street car where the power is made can be more important than how much is made. Too much cam and/or head and, unless you happen to get rear ended by a 747, you might be looking at some Hyundai's tail lights before your motor is making it's awesome power :). Just a cam and exhuast should get you to your hp goals but the right heads, in combination with the aforementioned, can double the power increase. Besides the benefit of increased flow, going to a smaller (and probably more efficient combustion) chamber will increase your compression ratio and power.

I'm a big fan of aluminum head just for the weight reduction, and especially because it's at the front end. It's easy to compare aftermarket heads if you don't care about anything other than price vs size. It gets more complicated when you consider the other critical components of the heads. Some mfg's advertise a great price but that price is with the cheapest valve springs, guide plates are extra, etc.. By the time you've upgraded that "bargain", you may have spent as much as you would have on a better head. If you're building a stock geared, L48 auto, you DO NOT want the biggest heads you can find. You want heads that will make power where your car can use it. While the Vortec's would be a good match to your combination, by the time they were upgraded with better springs and you bought a matching intake manifold, you will have spent almost as much as if you'd bought Edelbrock's or something comparable.