I loved the zf 6. had one for a yr or two around 05/06, in a dirtymax ext cab dualy. Then again in 09 with a 6.4 powersmoke f450. She didnt grunt much, but we had it bulletproofed. One of the few 6.4s in our fleet beck then that actually lasted. I cried in 2012 when it was time to get new trucks and found out u couldnt get sticks anymore. We could either wait forever for dodge to order us some slt, def couidnt get a stick in a laramie, or get a couple sterlings. From what I remember we got 2 auto fords and some of the last stick sterling. It was funny seeing the big S where the ram was supposed to be, kinda lik now the international cxt / mx line is a heavy duty chevy.