TH400 & D20 swap question.

[Logans Run]

I have a TH 400 mounted to a D20 Tcase on the bench. (1973)
In my rig I have a TH 400 mounted to a Q-track.(1976)
I have all 4 drive shafts both flex plates and both torque converters.
I even have the tranny extension thing from the (1973) non Q-track rig.
.
My question: Can I pull out the TH400/Qtrack combo, put the extension on, and bolt up the TH400/D20 combo?
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Do I need to keep the 73 torque converter with the 73 tranny, or can I bolt the extension to the 76 motor in the rig and then bolt the 73 TH400/D20 right to that (without changing the converter and flex plate)?
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And ... is there any chance I can make the drive shafts that I have work?
.....ANY input will be greatly appreciated!!
Thank you.

[Logans Run]

I just measured the distance from U-joint to U-joint.
73 rig is 87"
76 rig is 85"ish
so unless I can compress the shafts around 2 inches (and this may not be a problem because the 76 rig has a 6 inch spring lift) my drive shafts may need to be altered.

[Logans Run]

oops ... I guess I need to lengthen them ...
So I should probably count on that, at the very least.

[Logans Run]

I just got a quote for $300 plus parts to lengthen my drive shafts .. seems a bit high.

[Stuka]

The D20 wont bolt up directly to a TH400 that had a Quadra Trac. The output shafts on the transmission are different. It doesnt require a rebuild of the transmission, but everything has to be taken out and have the shaft swapped.

Lengthening drive shafts is always more than shortening. As the tubing has to be replaced, rather than just having it shortened.

[Logans Run]

Thank you Stuka, I am actually going to take the tranny AND D20 from the 73 and put it into the 76 as a unit. so I wont need to MAKE the tranny fit the D20 (because it already does).
------------------------------------------------>I guess my big question now is, will the 76 flexplate and torque converter (already on the 76 AMC 360 in the rig) fit the 73 tranny (and I will also install the 2 inch spacer/adapter with the 73 tranny)

[Stuka]

Ahh ok

Oh, and as far as I know, as long as you use the spacers you will be ok.

[Logans Run]

Thank you.
I will let you know how it goes.
Its on 35" tires, and has a 6" spring lift so my tranny jack wont go high enough. I plan to build a jig to bolt onto the jack that adds enough lift to put it in.
So hopefully by the end of the week I will be done and my drive shafts will be getting lengthened.

[Ryan]

$300 for dshafts is a decent price. That should include lengthening both shafts, balancing and new u-joints, as well as a new ball-kit for the front CV shaft.

[Logans Run]

Didnt work

I ran into a snag, the converter was pretty torn up, it had one of the bolts stripped and most of the bolts holding the tranny to the engine were either lose or missing.. there was only one bolt that was actually tight!!
I have a line on a new used converter, and I will try it again after Turkey day.