Dodge D100 project "Grim Sleeper"

Hi guys I've recently bought a mid 70's dodge D100. My plans for the truck are to build it into a sleeper. It has a bone stock 318 and 4 speed (NP435). I'm planning on building the 318 but would like to swap out the 4 speed for a car 4 speed and do something to the rear suspension. I'm looking for as much help as I can get, and what better place than FABO. The best thing about this project is I only paid $400 for the truck, and the cab and frame are both solid as hell. My plans are to lighten the truck as much as possible and set the motor up with a 100-150 shot of nitrous. Like I said I'm looking for as much input as possible. Any and all help is gratefully appreciated.