well here is what i have. i have two 73 f100s. one is a 4x4 with a C6, and the other is a 2wd with a 4 speed. i had asked this question befor about if i could convert the 4 speed to a 4wd 4 speed. i got a good responce sayin i could by changing the out put shaft and the intermediate housing. my problem is where do i find parts??? i have asked a local parts distributor and he came up empty handed. so any help tracking down parts would be greatly appreciated.