i'm getting ready to build my motor,a 1997 gsr (at my uncles machine shop) and i am confused about the rods i purchased. i know the gsr rods have a p72 casted into them,and no R marking, so i bought what i thought were type r's, as they had an r forged into the beam. however the rod cap has a p72 forged into it...........i thought type r's were p73? anyways the rod bolts have the dimples for a stretch gauge, and the caps are not different (there perfectly round, and have a weird paint number mark covering both rod and cap at the split, they all match correspondingly. my question is does anyone know if there is a type r with a p72 casting number? as i want the strength of the r rod, but am not shure if thats what i ended up with. thanks guys