[Steeveedee]

I don't recall seeing vapor recovery canisters on 3/4T and larger trucks in '71, and for certain they didn't have EGR. So there has been some swapping around going on. Has the cab on your truck been transplanted from a different vehicle? If so, and it was more recent manufacture than '71, it could have the vapor separator lines in the cab. It'll be obvious from looking at the tank, as there will be multiple lines to it, not just the fuel pump suction line. What does the SPID say about California emissions equipment?