Just wanted to add that in the 400 sbc blocks, the opposite is true...2 bolt blocks are better due to the cylinders being so close together (siamesed) As long as you are not spinning the motor over 6krpm on a regular basis, it should hold up fine with cast parts. Anything over 6krpm (racetrack visits, nos, etc) and forged components are the only way to go.
Dano
