So from what they say the 6s were Chevy 230 motors. They list the two as having different compression ratios so my guess is the differences were in the head and cam much like the 8s. And of course the carburetor, but that doesn't have a being on CR. So I'm thinking chamber size and maybe head gasket thickness. So essentially you could probably take a base OHC 6 and turn it into a sprint motor by decking the head or block or both and changing cams. You'd still have to add the 4bbl. Sound feasible? Was there sprint badging on the motor itself?