I have a '91 Z28 350TPI ,and I just got my racetronix fuel pump package in the mail, which comes with all new wiring to "hotwire" the fuel pump to up the voltage. Everything is premade w/ instructions. It has a 3 prong plug on the end that I'm guessing is for the sending unit. My question is, I thought I saw somewhere that the pre-90 cars had a 3 prong plug & the 90-92(which mine is) has a 4 prong. Anybody know for sure? Thanks.