I used the formula of dispacement x max rpm. The other formula in the Holley book seems to point to a 750 as well. A buddy has a 650 on his 318 and is very happy with it, and at $330 it seemed like a good deal with all the features.
I also thought a Proform/Quickfuel 750cfm generally flowed higher and a 750 would be plenty. There is a link to another thread with engine specs on page one. After you read them, tell me
what carb you would have picked.
