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.

 

The ITR head uses the same casting as the B16, hence the PR3. My B17 also has PR3 stamped on the head.

The ECU, pistons and cams are specific to each exact engine so they have unique codes. I don't know if there are actually numbers stamped/cast on the cams but those are the codes.