Depends on what T56 you want to use. If you're going for an LT1 T56 you'd need the special flywheel from Centerforce because your SBC 400 is externally balanced -
http://www.summitracing.com/parts/CTF-700173/
Then you'd need an LT1 T56 clutch/bellhousing/hydraulics, and fab up a clutch pedal (3rd-gen F-bodies make good donors for adapting to the G-body), or you can buy one from this guy -
http://www.gsi-interiorss.com/item/t...-cu/lid=983837
After all that is done, you'll have to mod the crossmember (or buy one for a 700R4 in a G-body) and have the driveshaft shortened/balanced.
The ~cheaper~ alternative would be to go with an LS1 T56 and McLeod Industries sells an adapter plate which allows the T56 to be bolted to a standard Chevy bellhousing and is about 0.5 inches thick. They also sell an extended pilot bushing which makes up the 0.5 inches lost to the adapter plate. With this setup you can run a G-body bellhousing, mechanical clutch linkage, and 400 flywheel and clutch setup. You'll still have to buy that set of pedals, and the crossmember/driveshaft mods still apply.
Either way, rowing your own gears in a Monte is lots of fun, but can be a royal PITA.
