[68c10airstream]

Just source a used or rebuilt up through 1985 c10 2wd gear box. It should be a 3 1/2 turn lock to lock variable ratio box that will give you nice road feel and assist. If you start swapping internal parts you most likely will run into the difference between fixed ratio and variable ratio issues, as they are NOT interchangeable. These gear box's are outside frame mounted, o ring style lines. Good luck.