been checking out some of the gm crate motor and they are making decent power and torque- 400bt lb range with very mild cams. so obviously heads are where its at. can stock chevy heads be ported to flow as good as say some torquers or sportsmen IIs? or would it cost just as much as buying aftermarket? i think that 400+ ftlbs out of a small block is pretty good. the zz4 makes this with only a 208/221 cam. any one have anything to add to this- personal building experience??