Time to describe the swap from SM456 to NV4500. I do plan to go into a little detail here because there were a number of things I ran into that I hadn't seen in other NV4500 swap threads.
This will be like time-lapsed photography because this swap covered multiple weekends. It took a good bit longer than anticipated, but if you've been following my build you'd know that it would have been more of a surprise if it went smooth and quick
So this all starts back in January of 2012 - maybe earlier - when I started collecting parts for an NV4500 with NP205 for another project that still hasn't gotten off the ground. I got the NV4500 from a 92 donor truck and a NP205 transfer case from a rusted out 76 K5 Blazer donor. Turns out that the NV4500 is apparently a newer model that had been transplanted into the 92. The axles I've already posted about swapping came from the same Blazer. I had the NV4500 and NP205 "gone through" by a drivetrain shop back at that timeframe so they were ready to go. I'd ordered the Advanced Adapters NV4500 to 23-spline NP205 adapter (50-0218) and bellhousing 712577 along with a bracket to mount a slave cylinder for a hydraulic clutch. It all sat for years while the rest of this build went on. The drivetrain shop that did the NV4500 work also did the required cut on the tailshaft and mounted the new adapter/tailhousing, etc.
So a few weekends ago I matched up the NV4500 and NP205 for a test fit and to mount the shifter bracket, etc. I'd read that the AA bracket for the NP205 shifter was kind of flimsy and that turned out to be the case. So I added to the bracket so it would have a little more support. That seemed to work fine. But the little s-shaped linkage to the shift bar would not line up and fit at all. I ended up trying to make one of my own. It did fit, BUT I could not get both the front and rear ends of the rail to shift together. I could kind of juke things and get them right, but that wasn't going to work with the transmission hump in place and not being able to see how things were aligned.