My dad has a 67 SS 350 that has an off-balance engine. He told me if i wanted to i could build one for the car. I don't know what to choose. if i could find a #'s matching block i would make it a 350 cuz the car is all original. if not i wanted to build a 370 (that's a 3.625 crank with 4.030 bore) with vortec heads. i want this engine b/c i think that it will have less crank clearance issues and will last longer than a 383 b/c of less piston speed.

Are my assumptions correct? Does anyone know where i can get a #'s matching block for a 67 SS?