Driveshaft Q's

[Steve Sherman]

My 86 5KTQW needs a new driveshaft (bearing is loose and so is the
Ujoint).  I am considering getting a used one, but one of the local
shops here told me they had a shaft from a 4Kq that they had put a new
bearing on but never installed.  While it seems unlikely is there any
chance that the 4K shaft would fit the 5K?

Second Q, does anyone have part numbers or the like for getting the
parts to redo the Ujoint?

TIA

Steve