I am building a 493 for my 63 and I am using Indy EZ heads. I had to get the dished piston to get my comp down to 10.6. I am using an agressive cam that Dwayne Porter speced for me. It should run fine on 92 or 93 pump. The cam has alot to do with it also as it can have a big affect on cyl pressure which they say keep it below 190 for pump. Ron