They had it worked out pretty well in 07. The 6.4 engine and 6.7 engines that replaced the 6.0 are being labeled these days as "disposable". I'm reading that many more parts are NLA for the 6.4 than for the 6.0 even though it's a newer engine. Kinda like the Toyota 3FE
I still cant figure out how a diesel guy like yourself went with the 6.0.