I just ordered the 512 kit and heads today from 440 source. Ken told me the 512 was a better choice than the 493 that i was going to go with.The 512 should yeild about 10.25 compression where as the 493 was going to be about 11.5.

1957 Dodge truck, Snakeskin Green with a little stroker motor. 1964 Plymouth Savoy wagon ( my new project)