Power Recommendations Needed….

DO2G

DO2G

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Joined
May 10, 2008
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23
Location
Cheshire, CT
I have a 1978 L-82 with a 4 speed. I have true dual exhaust and edelbrock intake. Everything else is stock. I’m looking for a way to add some more power without replacing the heads.

Is there a replacement cam that I can use that will provide more power and allow me to keep everything else as is and also not have a problem with vacuum? If so, please recommend which cam and lifters if needed I should use.

Thank you
 
You have 462624 heads 1,96x1.5 valves, 76cc chambers and 150 or so cc intake runners. They are open chamber smoggers and don't make a whole lot of power. A cam swap will do some good since the L82 cam isn't anything special either.

Question is, do you want to upgrade the springs or don't you want to touch that? About the biggest you could use in case you want to retain everything else is the 260H or something equivalent.
 
DO2G said:
I was hoping to leave the springs alone, but what do you recommend with changing the springs? Would it help with a performance gain?

What do you think of this kit? http://www.summitracing.com/parts/CCA-K12-206-2/?image=large

Also, If I went with just a new cam 260H would I need new lifters?
Click to expand...

When you change a flat tappet cam, you always change lifters.

That cam you listed is smaller than what the L82 came with.
You might have better low rpm torque, but would likely make less power overall.
 
Hey Grayson. Long time no see.
Alot of people have good luck with a GM151 cam in stock engines.
 
The heads on your motor are going to be the biggest draw back, Edelbrock has some pretty good upper end packages,you might want to check them out,price is pretty reasonable.
 
What do you guys think of this set up with stock carb and true dual exhaust?

GMPP Vortecs (P/N 12558060), $600
GMPP Self-aligning stamped-steel rockers (P/N 12495490), $60
Edelbrock Performer EPS intake (P/N 2716), $185
 
The L82 cam isn't all that bad, I'd upgrade to a hydr. roller cam but your biggest problem right now are the stock heads...if you're going to install a cam with significant more lift/duration you should get rid of the pressed in rocker studs.
Performer EPS ?? You can have my Performer intake for $50 plus shipping - pm me if you're interested.
 
I do not believe that the stock rocker studs and springs support any cam with more than .500" lift, Edelbrock RPM heads are the cheapest quality product out there. These are good heads for the money ($1000/pair) and the rocker studs are "screw in" style and the springs are good for .575" lift. With 64cc chambers you'll bump the compression a little and the 170cc intake runners are ok for a mild 350. As always: you get what you pay for. CNC profiled Dart/AFR/TrickFlow heads that cost about twice as much are probably giving you some extra HP but that might be overkill on a stock short block....

My old combo was a L48 with flat tops, basically bumped the CR to what the L82 has, 9.5:1
With RPM heads and the performer intake and a Performer cam it ran pretty good. That cam was a lot milder than what you have now.

I'm sure that the RPM heads, stock L82 cam, Performer intake (fits under stock hood) is a pretty nice combo for you. You already have forged pistons with 9.5:cr, with the smaller chamber heads you should be at around 9.8:1. It should work really well for the money spent.

You can then add 1.6:1 ratio rocker arms to get more lift, the springs that are installed in these RPM heads will support that easily.

Procomp/Summit/Jegs heads might be $200 less but Marck (TT) had some ugly photos of these castings....
 
MYBAD79 said:
I do not believe that the stock rocker studs and springs support any cam with more than .500" lift, Edelbrock RPM heads are the cheapest quality product out there. These are good heads for the money ($1000/pair) and the rocker studs are "screw in" style and the springs are good for .575" lift. With 64cc chambers you'll bump the compression a little and the 170cc intake runners are ok for a mild 350. As always: you get what you pay for. CNC profiled Dart/AFR/TrickFlow heads that cost about twice as much are probably giving you some extra HP but that might be overkill on a stock short block....

My old combo was a L48 with flat tops, basically bumped the CR to what the L82 has, 9.5:1
With RPM heads and the performer intake and a Performer cam it ran pretty good. That cam was a lot milder than what you have now.

I'm sure that the RPM heads, stock L82 cam, Performer intake (fits under stock hood) is a pretty nice combo for you. You already have forged pistons with 9.5:cr, with the smaller chamber heads you should be at around 9.8:1. It should work really well for the money spent.

You can then add 1.6:1 ratio rocker arms to get more lift, the springs that are installed in these RPM heads will support that easily.

Procomp/Summit/Jegs heads might be $200 less but Marck (TT) had some ugly photos of these castings....
Click to expand...

Do you know if the stock valve covers will fit over the 1.6 rocker arms? I put a lot of work into refinishing my stock valve covers.
 
DO2G said:
Do you know if the stock valve covers will fit over the 1.6 rocker arms? I put a lot of work into refinishing my stock valve covers.
Click to expand...

I don't know but they sell thick gaskets that will raise the valve covers slightly... FelPro FPP-1603 is .219" thick.
 
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You'll need to remove the oil drippers if you have the cast alu or magnesium (81 & 82) finned covers and thick cork gaskets and it'll clear just fine.

BTW, have some summit heads here, seem like nice heads, can't see anything wrong with them. Haven't taken them apart to check spring installed heights and such but out of the box, not bad. Casting needs a little cleaning up but that's it.
 
MYBAD79 said:
.....
Procomp/Summit/Jegs heads might be $200 less but Marck (TT) had some ugly photos of these castings....
Click to expand...

If you guys want me to post pics and detailed info of the set of PROCOMP (PC3003S) cylinder heads I am now installing on my 383, I'll be happy to do so here on Vettemod. My PROCOMPs are machined in USA and casted in China, like my Scat crank, SpeedPro pistons and lot of other parts I bought in the US for my 78 Vette. I believe the Procomp and Patriot cylinder heads have got bad reputation because of misunderstood rumors. How can they be that bad, when are sold in thousends and very few complaints as far as I have seen? Anyway, the cylinder heads I have here on my workbench, are of high quality and do not have any bad castings!

I am also installing Edelbrock Performer EPS Vortec manifold on this build.

best regards
Arne
 
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arneoe said:
MYBAD79 said:
.....
Procomp/Summit/Jegs heads might be $200 less but Marck (TT) had some ugly photos of these castings....
Click to expand...

If you guys want me to post pics and detailed info of the set of PROCOMP (PC3003S) cylinder heads I am now installing on my 383, I'll be happy to do so here on Vettemod. My PROCOMPs are machined in USA and casted in China, like my Scat crank, SpeedPro pistons and lot of other parts I bought in the US for my 78 Vette. I believe the Procomp and Patriot cylinder heads have got bad reputation because of misunderstood rumors. How can they be that bad, when are sold in thousends and very few complaints as far as I have seen? Anyway, the cylinder heads I have here on my workbench, are of high quality and do not have any bad castings!

I am also installing Edelbrock Performer EPS Vortec manifold on this build.

best regards
Arne
Click to expand...

Yes, pictures would be great. :thumbs:


I have China heads on my Vette right now. Been over two years.:)
 
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