Dumb question - Quaderbreed 700R4 adaptor plate to mate to a T5 manual transmission

Forgive me if this is a stupid question. I have a 1975 XJ12C which came with a 700R4. I keep having designs on putting a manual gearbox in it and was wondering if the adapter plate can be used to mate T5 transmission with a GM Bell housing.

I’m hoping that someone who knows can give me some insight. Thanks

@Jeff_Schroeder… any help here?

I don’t see why not if you can get a T5 with the right input shaft length. The adapter plate converts the v12 to a Chevy bolt pattern, and there should be plenty of Chevy to T5 bellhousing options. The devil is in the details as far as input shaft length, clutch linkage, etc. But the concept seems sound to me…

Thank you. This is helpful

To clarify, you are asking to mate a T5 to the 700R4’s bell housing?

If so, that’s not a road you want to go down. Here is the setup you want to use with a T5:

Thanks @Jeff_Schroeder - This appears to be NLA

Shoot them an email / they are still available. I believe they have them done in batches. I just got one 3 months ago.

Thank you!

1 Like

Is the adapter plate between the block and the bell, or between the bell and the trans?

AFAIK, all 700R4 transmissions have an integral bell housing (part of the main case casting). Easiest solution is the 5speed.com bell. You should also be able to use your current adapter with a GM bell housing, but you will need a crankshaft adapter of some sort to accommodate the adapter thickness, and you will need a GM length input shaft. Problem with the GM T5 is most were canted 20 degrees so mount fabrication becomes an issue.
You can get a SN Mustang T5 with a longer input shaft, but it probably will require machining to work.

That’s sort of what I was thinking. But it does increase the parts count, as you observe.
I’m happy with the 5speeds.com bell, but it does need to be indicated and centered using offset dowels. My experience with two QuickTime bells is that they are pretty close to dead nuts. Not sure if you can special order a Quick Time or not.

Thank you everyone