ok, i'm pulling the 2.8 v6 mpfi engine out of my car. i'm putting in a carb'd 383, what wire harnesses should i keep so i can run my stock gauges and accessories and which ones dont i need? also, i pulled a silver box out of the right side of the dash that had about 50 wires going to it. what is that? and is the computer the little black box right by the diagnostic port? any help would be great