I believe the 170 ft.lbs figure is incorrect.
BV Motorsports has one bolted to a turbo 3800.
Trinten has one bolted to a small block Chevy that makes about a million horsepower. (An exaggeration, of course, but it's seriously around 400.)
I have an NV T550 (late Getrag 282) bolted to my 4.9. It's only about 220 HP, but it's a torque monster. Probably ~300 ft.lbs. Haven't broken anything yet.
[This message has been edited by Raydar (edited 07-31-2013).]