[zimmy]

Hey, Folks:

Thanks for the help. Here's what I know. Engine had 390 truck crank with standard 427 stroke of 3.78". Standard length Ford rods. The TRW pistons had a short compression height. Apparently, the original builder cheated me by using 390 heads with the casting numbers ground off instead of the 427 Med Rise heads that I had thought I paid for and got. Block was also 0.030" over instead of stock as promised. We didn't actually cc the heads, but they were estimated by an experienced builder to be about 76 cc. With all of the measurements that could be made or estimated, I calculated the compression ratio to be about 8.5:1. The Webers like it to be about 10.5 or 11 to 1. No wonder I had so much trouble getting them to run right. No where near enough air getting pulled in. The smaller valves of the 390 heads didn't help either.

New engine will have 10.5:1 with nicely worked Edelbrock aluminum heads and a stroker kit. Expecting about 500 hp. Keeping my fingers crossed.