CTR INTAKE CAM ID: As you can tell by the picture (which I got from the Tiiite/Hybrid board) the CTR intake cam has two rings on the end of the cam. The GSR and ITR cam do not have this double ring and it is specific only to the CTR intake cam. All DOHC Vtec cams have distinctive markings on them. Newer (92+) Vtec cams have 'engraved rings' around the 'distributor key' portion of the intake cam. (CTR cam shown)

Cam install link from the Hybrid board-- Adrian Teo's cam install.
Information taken from-- Katman's JDM ID site.