I took the exhaust and valve covers off my sbc 400 and saw I dropped a valve in cyl. #5!! The block is a 4 bolt main 400 and the heads are stock 76cc 1.94/1.50. Looks like the rockers were upgraded to roller tips, so I am assuming a mild cam was placed. What heads should I get. It has performer intake and Holley carb. Should I go with aluminum heads? Is the intake adequate? I want to re-build it to 450-500 hp.

Thanks

thedonz, I think to make that kind of power you will need to upgrade the heads. Maybe not aluminum but a better aftermarket iron head at least. I also think you will need a roller cam shaft, and roller lifters. You might be able to get away with that intake. As far as the carb, what are the specifics? What exhaust are you using?
Dave

Just open up a Summit or Jegs catalog an they have a top end package for small blocks that you can get for around 2500.00 with everything. Have a good engine guy run through the bottom end and 450 -500 hp should easy to obtian and reliable.

AFR heads seem to be about the best, I am building 383's right now, and I went with Bowtie Vortecs.

thanks guys....what compression ratio would I need for that kind of power? Doeas anyone have a good cam they can recommend for performance marine use?

PM RM BUILDER HE CAN SPEC OUT A CAM FOR YA.

And some new AFR Eliminator 195cc's !

Intake will need to be an RPM or Vic Jr. The regular performer will stomp out (extinguish) airflow and power big time.

Well, it looks like I can only salvage the internals and need a solid 350 4 bolt main block to stroke. Her's what I saw when I removed the heads.....

cylinder #5 wall has a BIG chunk missing.......duct tape won't hold it together because of oil.......

Jolla Amigo
I would have that hole sleeved. Block decked and line honed. I've had my blocks sleeved with no problem at all. May save you some coin but then again small blocks are fairly reasonable. Stay away from Merlin heads. They are thrifty with the nickel content if your going to run with cast iron. GM or Dart would be my choice.