Hi all,

I bought a '76 3/4 ton Chevy truck with a 454 in it that was supposedly rebuilt to stock specs 30k miles ago. The only non stock items are exhaust headers and a 750 cfm Holley carb with a 1/2" spacer; I pulled a valve cover today and found that I have 781 heads. The engine feels extremely strong as it sits, so I'm leaning towards running it as is for a while. My next step is to swap it into the Chevelle. How much power is this engine likely making now? How much more could I make with a cam and intake swap? I was thinking along the lines of a 270 advertised duration cam and a Torker2 manifold so I can retain the stock hood.

Performer RPM intake!!! headers,cam,carb and gears and you're in the 12's easy enough.

I know someone who took a similar engine and did nothing to the bottom end and now is running 11.90's with it in a pick up truck. All he did was put heads, cam, intake, headers on it and built a rear and transmission.

Compression will be the worst thing to deal with, open chambers need high domed pistons to get it even to 9:1. To run a decent cam you will ussually need more compression

Or you can do what i did - use a comp XE 4x4 270 which will keep your DCR where you want it and get some crazy torque to pull 3.08 gears which keeps my car highway drivable.

I stuck with the dual plane Performer intake for low end torque ans stock height.

-Ryan

Should be an about 7.9 to 8 to 1 stock CR. P/U motor......

Pistons should be true flat-tops and I think mine only came with one valve notch for the intake?

pdq67

Thanks for the replies, everyone!

Quicksilver--I like your idea of using the 4 x 4 cam to keep dynamic compression in line--I have a torque converter that stalls a few hundred rpm above stock, do you think it will work with the 270 4 x 4 cam? How about your power brakes?

Originally posted by TooSlow:
Quicksilver--I like your idea of using the 4 x 4 cam to keep dynamic compression in line--I have a torque converter that stalls a few hundred rpm above stock, do you think it will work with the 270 4 x 4 cam? How about your power brakes? Yes, i did it because it was a large enough cam for the heads while still keeping my dcr up there. I have a few bugs to work out with the motor but i have a 2k stall convertor and a shift kit in a TH-350 and power brakes that work fine.

Motor is a .030 over 454 Stock rods and crank w/ ARP bolts throughout, Merlin Iron heads with 2.30 valves (mistake - i ordered 2.19's but didn't bother sending them back) Performer intake and Demon 750 carb. The pistons are hypers - slightly domed and give me around 8.75 or 9:1 compression.

Likes to idle round 800 rpms and revs nicely to 5k with my 3.08 gears. Runs on 87 octane fine, and stays really cool with two electric fans and a 4 core rad.

My car isn't insured and even worse i have the body off for a frame swap right now so i can't really tell you its strengths or weaknesses.

-Ryan