ZF Transaxle

This may be a good deal depending on whether it is as advertised. Of note, in order to use this in a GT40, you have to have this transmission flipped over from its' Pantera conformation. This is worth doing if you get the unit inexpensively enough. A unit completely rebuilt from RBT is about 7K, so if this one can be bought for less you would still have room to have it turned over and be set up for a GT40.
The ZF box which was intended for the BMW M1 will also fit, without turning it over. This was used in the Safir GT40s, and it is what I am buying for my GT40 project.