It should be rather obvious that increasing the compression changes the fuel octane requirements You would have about 10.5:1 with a 350 but closer to 11.4:1 with a 383, theres 43.75 cubic inches of volume in a 350s cylinder and 47.8 cubic inches of volume in a 383s cylinder. 042 thick head gasket and a 67cc combustion chamber cylinder head, you would have markedly different true static compression If we were to assume you were to build very similar engines differing only in the stroke and piston pin height and you built either a 350 or a 383 engine were built with a flat top piston that reached TDC and had the pistons top surface equal in height to the blocks deck height, and both were built using a. GRUMPY ? What does the increased cubic inches have to do with what octane fuel you use?

Viewtopic.php?f=55&t=624&hilit=port+cross+section RELATED THREADS, it might take you several hours to read thru these but you'll save a lot of time and money doing so! rather that just buying parts first Match the drive train gearing and converter stall to the engines intended power band MATCHED ,CAM TIMING, PORT CROSS SECTION AND LENGTH<

Comp cam 350 sbc