Need at least 4" of lift to run an external slave NV4500. Mine is lifted 4" and only has about 3" of clearance. I haven't hit my driveshaft yet, but I haven't flexed it right out yet either...
There are two big challenges to overcome with the swap. One is the transfercase shifter (assuming 208 or 241). The NV4500's shifter sits quite a bit closer to the seat than an SM465's. While the you can cut a hole in the floor for it, and make the trans fit with the t-case shifter installed, there is not enough room for a shifter boot on the NV4500's stick. You either need to install a different shifter for the t-case, or find a really tiny shifter boot for the NV4500.
The other big challenge is with the clutch master cylinder. While I have heard rumors that you can use a factory 85+ clutch master & simply splice the lines with a quality compression fitting (I use Swagelok rated for 22 000 PSI), I have not confirmed as much yet. On my last truck that I had the NV4500 in, I installed the master cylinder from my 93 donor truck onto my older truck, and installed my own stud on the clutch pedal for hooking it up. While it worked, there was a bunch of pedal effort introduced, and there were some indications that there was too much change in angle for the newer master cylinder across the throw of the pedal and that it would probably have failed pretty pre-maturely.
