It depends on which direction you want to go with the T-56. OE or Aftermarket. OE will mean you'll need a complete T-56 setup including the clutch assembly (make sure it's complete - the T bolt isn't avail from GM anymore). Depending on if your block/crank is pre or post 1986 you could also need a special flywheel. Pre-86 is 2 piece rear main as I'm sure you already know and will require a different flywheel.
If you go aftermarket, you can use a traditional clutch setup, flywheel, etc.
I hope this helps. Let me know if I can answer any LT1 clutch setup questions. I've done a couple of them.
Try calling Mcleod's tech support, they were extremely helpful and knowledgeble when I had questions on which flywheel and clutch to use. Good luck, it's the best thing I ever did to my car
__________________
1962 Nova, LS1/ T56, DSE Mini tubs and subframe connectors, Church Boys 4 link, Viking coil overs, C6 brakes