[MDSHARK81]

I was looking at 1971 books and came across prop shaft usage chart. If I’m reading correctly looks like for F body with 3.42 (which I have) the D-shaft was same length (48”) and with the same trans yoke??? No difference between shaft from auto to manual? Is that correct?

[johnta1]

Same length (48.55), and with your Muncie the same tranny yoke. (big, 32 spline)

[MDSHARK81]

Question on the drive shaft ends:
1-Trans yoke ? 32 spline output from M-22/T400 to a 3R series U-joint? (Spicer 5-795X u-joint?). Also long (7 5/8 end to center of joint) or short (5 3/8 end to center of joint)???

2-Pinion flange end again Spicer 5-795X u-joint? I measured my pinion flange on diff and it comes in at 3 5/8 wide with 1 1/8 end cap width. this joint uses inside retainer clips like stock pontiac.

Thanks for help

[johnta1]

If your driveshaft and yoke/pinion are original, use the factory u-joint for it.
My problems were always using a old M20 tanny with the newer TH400 shaft, which did require a conversion joint. Or a chevy shaft to a Pontiac.
I have some conversion joint numbers but they are over 20 years old. Your numbers I don't have. Doesn't mean they are correct though.

You have the bigger tranny output yoke or looking for one? The shorter one is probably what came on it originally? (on Firebirds I have seen)

The rear end if not changed should fit if a Pontiac shaft?
(other problem I had with chevy shaft, it wouldn't mate to my 12 bolt)

[MDSHARK81]

Thank you for the response. My car still has the original (born with) engine, trans, & rear. The unfortunate part is the original drive shaft didn’t make it back from the bodyshop. I am now left with the task of reproducing one. I have located a DS from an early base bird. The trans yoke and pinion joint are wrong, but i can change those. The shaft itself is 48.5” in length. Which is the stock length I need. I believe I have found an original short trans yoke (32 spline). After measuring the pinion flange on my diff ( 1 1/8" end cap width diameter, &. 3 5/8” end to end) I’ve determined the SPICER 5-795X would fit. That joint is listed for the GM 3R series. It also has the “C” clip retainers on the inside (Pontiac Style). Once I receive all the individual parts, my hope is they all play nice together. I am crossing my fingers that my Frankenstein experiment works!!! In theory it should, but I’m sure I may have to tweak a few things.