Hi Guys,
The M1 components did come along later, mine is installed and more than capable of handling the 427 Windsor output.
The man who put mine togther is Steve Wilkinson, his company has been dealing with Panteras for 30+ years and if you go to his web site you can see a complete Illustrated Parts Breakdown of the ZF internals. Steve does have ZF transaxles in stock and can build one to your specs.
http://www.panterasbywilkinson.com/
Steve put my SPF together and did a great job, his shop is a custom Pantera shop and he has Pantera there with 700 HP+ that have been delivered and he is building more exotic rides right now. Steve also has a wide selection of DeTomasco parts that he bought in Italy when the company was liquidated.
TR