| Have a look on his website - Banks has a long history with Chevy, but builds engines and "kits" for most domestic lumps these days. That particular motor was a 6.0l built with a Dart block and lots of other goodies, and produced somewhere around 1100 BHP @ 6800 with 20psi of boost.
You'd be hard pressed to find a transaxle that could handle the output of that thing, and as others have said, for a GT40, 350-450 BHP is apparently plenty of power anyway. After all, it's really a 2000 lb racecar that's also street legal, not a 3500 lb Mustang, trying to be a racecar.
John |