My long wheelbase '73 F-100 has the two piece driveshaft. I'm about to pull the 3 speed manual and drop in a C4. The C4 is about 7" longer then the old manual.

I'm thinking that the easiest way to get the driveshaft to work is to scrap it and go with a single C4 yoked shaft.

Has anyone done this? Is it just as stable? Where there any shaft angle problems?

And finally, since the present manual has a bolt on yoke at the back of the tranny with somewhat different demensions then a stock C4 yoke, how would I measure to know what to look for at the boneyard? Thanks for any help, Polkat.

 

Polkat, I have seen long wheel base Fords with either two shafts or one, I do not know the rhyme or reason. Do you have a local shop that builds and repairs driveshafts? They will be your best source for that kind of information.
You can use the yoke from a C4 or an AOD, I just checked the ones in my shop. Count the number of splines and measure the bushing I.D. in the tail shaft, for the O.D. of the yoke, length will not really matter until you start figuring out your driveshaft length. Good luck