[KiltedBanshees93GT]

Are you looking to put a "period" transmission (ie 4 speed) in or a late model like a t-5? Either way you'll need the clutch pedal and all assorted hardware that goes with it.
I would imagine doing an older tranny would be easier, since the car was built to fit it,but youre still going to have to add the pedal and associated stuff, change from a flexplate to a flywheel, change the crossmember, and probibly lots of other stuff I'm forgetting.

If youre interested in adding a late model transmission, there is all of the above involved, and possibly having to shorten the driveshaft etc.

Somewhere down the road, I'm planning on doing the late model swap, there are conversion kits made by several companys to swap in a t-5 or tko into a classic stang.
I had these in my favs, there are plenty of sites out there with info for this swap.
This one has several other pages linked with swap info as well
http://users.ev1.net/~gbuzek/t5install.htm
This company specalizes in swapping in late model trannies and engines
http://www.windsorfox.com/

The biggest thing to remember is plan ahead, and gather ALL the info you can, that way you minimize the "oh crap, what now?" factor

J