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!!!

[Longhorn Man]

our trucks came with short shaft TH350's

[Solver]

Well Andy that sums up my answer in one sentence. Guess I'll have to take it and get it cut cause if ours all had short shaft, poking around in a yunkyard for the right one might be impossible.. My measurements show that if I take off about 3- 3 1/4" it should clear the rear end to slip it in the yoke. Not sure how much play there should be at the front where it goes into the tranny. My problem is that a short shaft tranny is 7" and long tail is 9" so thats only 2" difference in lenghts --but cutting 2 " out of front driveshaft wouldn't clear. Any enlightenment?
Thanks again for the info andy!

[krue]

Is your engine in the I-6 position, that would put in back another couple of inches.

[crazy longhorn]

A short shaft 350 T is a 6" tail (not 7), vs your 9 " tail trans.....there is also a 12" long version. as far as the engine setback, the I 6 sits 3 1/2" back from sb V8 position. Now if you are on BB stands, you sit approx 2 1/2" back from sb position. my guess is that the trans swap will get you rollin, unless you arent in factory position with the engine...... L

[Solver]

6"---That makes more sense now.
If factory was 6" tailshaft taking off exactly 3" should make the shaft fit. Or Am I forgetting some other measurement add in?
Hope the machine shop is open tomorrow!
just had it there a day ago to get the carrier bearing on.

[Brad]

Once it's all bolted in you should have approx. 3/4" before it'll hit the trans.

[70GMCer]

would be a lot easier if you could find a 6" tranny tail shaft.....

[Solver]

Don't I have to tear the tranny apart to swap tailshafts?
I don't think I could just swap housings as the shaft would still be to long.
Never messed with trannys much. I have popped tailshaft housings to swap speedo gears but thats all.any input?
I am sure I could find a 6" housing but not sure whats involved from there
70GMCer

[Myself]

Originally Posted by Brad

Once it's all bolted in you should have approx. 3/4" before it'll hit the trans.

I agree 3/4 to 1" before the driveshaft bottoms out will be just right.

[Green Machine]

Maybe if you could find the front driveshft half from a 6 banger, either 3 speed or turbo 350, since the 6 banger sits back about 3 inches farther than a V8, well it should be 3 inches shorter - bolt in deal ???

[BarryB]

Originally Posted by 70GMCer

would be a lot easier if you could find a 6" tranny tail shaft.....

Yes you would have to tear the whole transmission apart , just to replace the output shaft. Oh for extra knowledge, and th400 has a bigger shaft coming out. so a th350 driveline wouldn't fit anyways. a muncie M22 has the bigger shaft also. well it wouldn't fit unless you swapped the yokes.