I've got a 1991 C1500 reg cab truck that I am currently doing body/paint for, I was thinking about refreshing the drivetrain while I already was working on it. It's got 200,000 miles on the original 305 motor and 700r4 transmission, so I won't feel too guilty about taking it apart. I want to build a mild 350 in the ballpark of 370ish hp and was looking into manual swapping my truck. I'd love to keep an overdrive gear as I take it on the highway frequently and it currently has a 3.42 rear end ratio. What transmission could I use and still retain my factory ribbon speedo and vss? I want to keep the truck clean and use the factory parts as much as possible.