I have a 78 TransAm with a 400 bored .030 over. It has keith black hypereutectic pistons, stock rods that were resized with arp bolts, comp xe274 cam, 6x8 heads cut .060 that were ported. I have read where the block in my car is the 557 block which is not the best for a high performance build. My question is, do you think it would be worth putting aluminum heads on this engine and if so which ones? And if so, would I notice a difference? The car will not be raced. Just want a decent running car for the streets.
Absolutely. These are still good blocks. We do limit stroke to 4.00" on those since the mains are thinner. You would definitely notice the difference as the aluminum heads will flow much more. Just keep your compression (Hyper pistons 10.0:1CR) in a reasonable range and you will be good to go.
We even sell a new Engine KIt and Short Block Kit with 557 Block
Thank you Anthony. My pistons are flat top with 2 6cc valve reliefs. What aluminum heads would you recommend for my application.I see that you show edelbrock and speed master on your website. Also what intake manifold would you recommend and should I keep the xe274 cam?
The EX274 cam is a great cam and makes good power. Definitely not on the small end by no means. You could do the 72cc heads but would be a little over 10.3:1 CR. You can go Edelbrock out of box or have us build you a set using Edelbrock castings and Comp valvetrain. When we build your heads we fully blueprint and build to your cam specs just like a ported head. We can also start with the 87cc and mill to get you around 10.0:1 which is better suited for the cast type pistons. Lots of options when we start with castings only.