The ZF6 is a lot stouter. There are 3 versions though. The ZF S6-650 came in both the Superduty and Duramax equipped trucks. The ZF 6S-750 was used in 03'+ Superduty trucks. Both Ford version have an external oil cooler similar to automatics where as the Duramax version does not have this feature.
Even though the ZF has an aluminum case, it doesn't experience the same flex the G56 does mainly because of a third shaft support in the center of the case which the Dodge transmissions do not have. The main way to tell if you're looking at an ZF S6-650 and a 6S-750 is that the 750 has the bigger shaft and a larger tail shaft spline count at 34 splines.
I will be throwing one in my truck within the next few months hopefully, I already have the trans.
Even though the ZF has an aluminum case, it doesn't experience the same flex the G56 does mainly because of a third shaft support in the center of the case which the Dodge transmissions do not have. The main way to tell if you're looking at an ZF S6-650 and a 6S-750 is that the 750 has the bigger shaft and a larger tail shaft spline count at 34 splines.
I will be throwing one in my truck within the next few months hopefully, I already have the trans.