I've got my friends ITR head and cams (or atleast he says they are ITR) laying around at my house and I checked them out and I don't see anything stamped on the cams. When I looked at the head it had PR3-4 stamped on it, so what what is the stamp for ITR, is it P73 or PR3-4? Very confused! Is P73 the code for the ITR cams, b/c you were talking about cams.