11 1/2 :1 is a bunch of compression for pump gas. I have seen it done but every combo is different. I would use the thickest head gaskets I could find. You will also need to put a big cam with plenty of overlap to leak out some of the compression. While the heads are off I'd cc everything and check deck height. Hopefully the motor isn't a true 11:1 motor. Aluminum or Steel heads also act differently to compression and detonation. Walt
----- Original Message ----- From: "Mumper, Douglas" <[EMAIL PROTECTED]> Date: Monday, November 29, 2004 9:11 am Subject: [Chevelle-list] 400 chevy sb compression > Question: I just bought a 400 sb short block it has trw high dome > pistonswhich will give it 11 1/2: 1 compression with 76cc > combustion chamber heads, > can I get by with running SUNOCO 94 octane gas? Does anyone on > list have a > 400? If so how does it run, what carb, intake, cam, heads?? > >
