I spoke with Stephen at ORD and he hooked me up with Jantz 4x4 that builds the Jana 76 ring and pinion for the Dana 60.
The Jana 76 is the Dana 70 ring & pinion fit into the Dana 60 housing, this makes the Dana 60 33% stronger. With the power, tire size and weight of Thumper this is a must to strengthen the weak point.