They're 601 castings, from a 305. The chamber seems to be a good shape; would the overlap at the base (because of the smaller bore on the 305) cause any problems? I thought maybe combined with D-dish pistons I would get a good quench area and the thinner chamber at ignition time round the edges would decrease the chance of detonation. But that's just what I figured out. What other problems are there when you put 305 heads on a 350? Except for too high compression? Slowly I'm getting nearer where I want to be, thanks a lot for all your help,
Max