Rear gearing AT
 

Does anyone offer different gears to re-gear the auto tranny for track gearing?

The MT diff should be a direct swap. I'd probably go ahead and get a nice mechanical LSD, though.

Rear end is the same on MT and AT.
Parts to do a swap:
http://www.ft86club.com/forums/showthread.php?t=49288

How to do it your self:
http://www.ft86club.com/forums/showthread.php?t=54054

I'm not thinking the rear end but better ratios for the transmission.

I doubt it you will find any..... that would be a major operation .... ;)

You might want to fix your typo in the OP then since you say "re-rear"...

But I'd bet you would be looking at a different transmission which wouldn't be cheap. Haven't heard anyone complain about gearing in the tranny when the final drive can be changed and have a similar effect.
http://www.ft86club.com/forums/showthread.php?t=27647