i think south bend makes there's in house but not sure.

http://www.southbendclutch.com/inputshaft.html

also i ran there 13-1/4 CONOFE single disc clutch in my 2000 cummins with the NV4500that was making over 400 hp at there rear wheels with then stock size input shaft.i never had a problem with it braking and i was not easy on my truck. mopar65

3520 pound race ready 1973 Street/Strip Dodge Dart - Stock stroke 440/727 10.49 @ 125.0 on 93 pump gas & ET Street Radials. More to come... ( SGT Miller) Proudly served 12 years in the US ARMY RESERVES support our troops