Those are called ZF six-speeds, If it came off of an LT1 it should fit. If it came off a DOHC LT5 it wont fit the LT1. Make sure the bellhousing is with it, it will only fit the LT1. They are much bigger and heavier than a T-56 (145#). They are strong though, rated at 450 lb-ft. gear ratios are 2.68,1.80,1.31,1.00,0.75,0.50. You would have to make a custom mount, it's not the same as other tranys. The tip of the input shaft to case front-mounting fase for the LT1 ZF is 6.280 inches.If you need more info contactCorvettes by J&D at 562-804-5205, or S&K Speed at 631-957-9427. Hope this helps!!
------------------
http://members.tripod.com/~SnowSurfer/mikekz1.html