I'm planning on swapping a Cummins Turbo Diesel and manual trans (either NV4500 or NV5600, depending on what I find) into my crew cab dually. So far, I've been looking for only 4wd trucks (that have been damaged and/or will make a good donor). But, I have been recently thinking about running a divorced case. Since it's a crew cab, I've got more than enough frame length, but my question is this; how long is too long for the front drive shaft? Anyone ever heard of running a carrier bearing and two shafts for the front?