like I stated on the "canister post" my car didn't come with A.I.R., the codes for 72 LT1 are CKY, CRT, CKZ, the info I have states that CRT code came with A.I.R. CKY, CKZ didn't, mine is a CKY code,.......heres more to my story,  when I bought my Lt-1 the p.o. had the engine rebuilt because it would not pass smog, after the rebuild it still wouldn't pass smog, so in an attempt to have it pass he took the stock exh. manifolds off and bought a complete A.I.R. system ,front to back, when I test drove the car it ran strong, but it had a miss, and wouldn't idel less than 1200 rpm, when I got it home I replaced all the vac. hoses, passes smog idel's @ 900rpm like its suppose to, his mechanic's raped him, anyway I have a complete new vette S.B. smog setup sitting on the shelve.