McLeod will have their own bellhousing out in about 4 months that will help you out. I just spoke to them last week about that. Sounds like a great product.
Or you can switch to the LT1 style front cover and input shaft for the T56 - the parts are about $300. If you use the LT1 input shaft you'll need an LT1 hydraulic pull clutch and bellhousing, as the LT1 has a slim clutch and correspondingly short input shaft.
Or you could use the "aftermarket" input shaft along with the LT1 front cover and adapter plate. The aftermarket input shaft is longer than the LT1 shaft and along with the aftermarket adapter plate, allows you to use a T5 bellhousing and standard clutch, hydraulic or mechanical.