The small port heads don't have much meat especially around the exhaust ports. I'd be REAL careful. Might not be a bad idea to take one of those 270 heads and slice it up to see just how much you have to work with. The 302 and 270H large port heads don't have a lot to work with either. Actually the small port head performs well on a street engine, just don't stuff a big cam in the motor.
