[unruhjonny]

We are all guilty, and I am no exception...

What would I be guilty of(?);
I occasionally forget something.

Maybe I have forgotten this, and I'd appreciate anyone who knows this to speak up.

I had been given the understanding that second gen Firebird driveshafts regaurdless of drivetrain would interchange.

Disclaimer(!!) This should hold true as long as the driveshaft in question is set up for the correct size U-joints for the differential and input shaft.

Also, I had understood that 1970 model year cars had an unusually long input shaft.

I saw THIS "for sale" thread, and today something clicked;

If this driveshaft is too short for a manual transmission, then is my previous understanding incorrect?

I have four driveshafts;
I haven't run anything other than the 1972 M22 that my car came with (circa 1995), and since taking it off the road I have collected parts to run a different transmission - namely one with a 27 spline output.
i.e.: swapping to a TH350 input shaft

I had assumed up to recently that the 1970 Trans Am which my car has parts from, donated it's driveshaft to run the 1972 (Firebird coded) M22 that I previously ran - because of the oversized (i.e.: longer) input shaft.

I just measured the four driveshafts that I have (my measurements might be imprecise):
my 1970 driveshaft: 50-3/4" out to out of U-joint holders
two 2nd gen TH350 driveshafts: 50" out to out of U-joint holders
one unknown TH400 driveshaft: 49-1/2" out to out of U-joint holders

Question:
What should a s/t driveshaft for a 1970 Firebird measure?
vs
What should an a/t driveshaft for a 1970 Firebird measure?

Attached is a picture of the four driveshafts that I just measured - with my "original" (as acquired) driveshaft on the left.