The heads are Alan Root (AR incorporated) PRO 1 aluminum heads. My dad bought them in '89. The numbers that I have for them are .500 lift exh. 194 and 228 int. 1.94 int. and 1.60 exh. size valves. 58cc combustion chambers. No part numbers. First I was wondering if anyone has a set of these or if anyone has even heard of them? I was considering having them ported this winter for some more HP. I think the heads are my bottleneck.