Thanks for the reply. My car is a 72 - SS -L48 (Yes that how I got my username). On the built sheet it says N82 - Exhaust Emissions. That is the A.I.R. Smog equipment. Currently my car has all the smog parts on it, I was just wondering how to decode the pump. Now as you stated in 72 it could be a CA thing. My car original was sold out of Guaranty Chevrolet in CA.Cam said:I'm not positive about this but warrants double checking. From what I understand, the L48 came with a smog pump in 68/69 with manual transmissions, automatics didn't use them. Starting in 1970 the TCS (Transmission Controlled Spark) relieved them of the smog pumps for a while (through 1972). Starting in '73 the smog pumps returned on everything, as well as the new EGR valve. Investigate before shelling out. It may be contingent upon whetther it was California-registered or not.
Let us know what you find out. We can expand the body of knowledge about this sort of stuff!