Hey so I have a 77 f100 with a 460 and a c6 auto trans. I am going to change the auto out with a manual np435 transmission. In the process of doing this my drive shaft was to short for my np435 transmission. Does anybody know what size drive shaft I need to get and how I can hook it to the transmission(the drive shaft just slid into the back of the c6 but the np435 don't have a back like that) ?
if your np435 has a bolt on yoke you'll need a D-shaft with a stub & slip yoke in order to remove/install D-shaft. most likely you'll have to have one made...you need to measure from one yoke to the other (the flat surface of the yokes, not the pocket that the U-joint sits in)
since you have a shortbed I don't think you will need a carrier brg. ...more $$$ if so
I looked in the Ford parts catalog and, as Bill said above, there wasn't a 460/NP435 listed so I can't give you a driveshaft length.
With the flange style mount on the transmission you'll need the driveshaft, the slip yoke and the flange that bolts to the transmission.
Here is the illustration from the Ford parts catalog showing what you'll need for factory style set-up.
Click on the .pdf link.