Using 7.5" w/ '81 T/A Posi

[Bender21]

I am building a 2nd GP, this one from a v6, using a '68 Poncho 400. I have a '81 T/A that I am using for parts, mostly for the BOP TH350, snowflakes and its posi rear end. My question is what all do I need to convert the rear to use the T/A unit, and is it something someone inexperienced but with decent mechanical aptitude can do? I haven't opened one up before, so I have no experience. I need replacement axles for a GN correct? And what sort of kit do I need?

To convert the rest of the car I have already added Moog springs and new KYB shocks, dual exhaust crossmember, and a Summit radiator kit, w/ their 2-row aluminum radiator, dual 10" electric puller fans and shroud, as well as a transmission cooler.

 

[jrm81bu]

An 81' TA will have an 8.5 rear in it not the 7.5 that an 82' would. So the posi is going to do you any good for your existing rear.

 

[DRIVEN]

You would be much farther ahead to sell the T/A posi and look for a Gbody 7.5 with a posi and then do a disc brake upgrade. Your T/A rear is too wide and doesn't have the appropriate mounting points. Most of the Fbody rears had lame gearing anyway even though they were posi and had discs. Yours probably has something in the 2.73 range. I'm sure everyone will say "Just go get an 8.5" from a Grand National" like they grow on trees. Obviously, the 8.5" is stronger but the 7.5s are pretty sturdy if you don't blatantly abuse them. A Monte SS rear ('84-'86?) should have 3.42 and a posi. It would be a good match with your 400/TH350 combo. Good luck.

 

[Bender21]

Thank you for your help, I will start checking around for a Monte SS rear.