For this engine I used a Windsor block that was .030" over. I increased it to 4.35" and using a 4.00" stroke crank it cam out to 409.
I used a 258@ .050" lift intake dration and 12:1 CR. The heads are used C-3 Yates X NASCAR heads that where ported some more to from 388CFM @ .750" lift. With a custom built 1050CFM Dominator carb it made 735Ho at 6700RPM.