The 427 (and yes, GT40) suspensions are the work of Klaus Arning, and Ford Motor Co. he was the main chassis design guru in that era. Legend has it that the 427 was one of the first suspensions laid out on a computer...
To have a beer with him, show up at a SAAC national, he appears at quite a few of them. As a matter of fact, I wanted to ask him why the 427 used a welded on rear subframe as opposed to a full length frame rail (as a scratch builder here at CC has done). I just hope I can remember to ask at the next open floor at the nationals! I think it has to do with optimal cahssis mounting points, as I do recall that the rear arms on the 427 were a ' best compromise' because the original computer design had the forward points in the drivers arse. Not bad in a straight line, but I sure it hurt like he// over a bump!!