383...diff. year question...

65Val said

How did Mopar keep the same comp. ratio in a 383 when changing from early closed chamber heads to later open chamber heads? Early heads are ~73.5 cc's, and later heads are ~79.5 cc's. What changed to maintain 10 to 1 compression?...rod length, piston pin height???

Click to expand...

The early heads, 516 had a 84cc chamber. Although they are closed chamber it is still large. The 906 has more like 88cc. Only the 915 head was an honest 79cc. I think you have to take factory compression figures with a grain of salt. Im sure some were actually low 9s and some mid 9s and they advertised them the same.