Drive shaft lenghts?

[Solver]

Still trying to get my truck running after the fan shroud complication. (Averted that one by just sticking on a big block shroud).
Figured I was good to go. Went to put my driveshaft in this morning and the blasted thing is about 2 1/2 -3 1/4" to long. Now I was pretty sure a took it off one of my parts trucks with a 350/th350 but it sure won't shrink down. I know the tranny I have in the truck now is a 350 with a 9" tailshaft and I checked an extra th350 in the barn thinking maybe the tailshaft on it was shorter but --no 9". How many different 1/2 ton driveshaft lengths did they do for 67-72.There would be th400 , 3 speed manual, 4 speed manual then 350. Did each have different lenght? Also did they put short tailshaft trannys in our trucks?
Any input would be appreciated.
I have put a few trucks together but this one is really testing my patience!!!