so like Dr says, the 14ff stuff was so flawed they needed the products to repair vast numbers of them? I agree with his sentiment 'like most chevy products'It's super simple... Demand
or that marketing and parrot4x4 created the demand.
more likely china pricing dropped the cost low enough to be under what a replacement open carrier cost combined with parrot4x4.
it is far from simple. look how hard it has been to get aftermarket support for the best d60f that is available in vast numbers. still no chromos for the 05+ last I looked