The 4L60E is a computer-controlled 700R4- - - -they just changed the name to protect the guilty. The swap to OD is much simpler if you don't get into all the electronics, and there are a LOT of 700's out there. Find a S-10 with a 4.3 L V6 in it, and it will probably have a 700 behind the engine. Get the trans rebuilt with the Corvette OD clutch drum, and do your homework well on the geometry of the TV cable linkage. Mechanically, the two transmissions are almost identical, and you can even wire up the torque converter clutch system without having to get into computer controls.
Jerry