The NV4500 needs a speacial bellhousing, as it is a different pattern than a standard gm 4 or 5 speed transmission.
I have never put one in a 4wd, but I mention the dodge version because the imput shaft is 1 inch longer, allowing for a 1 inch adapter plate to be used between the bellhousing and transmission. The 2wd NV4500 is pretty long, so it might require pushing the transfer case back, which would make it necessary to make 2 or 3 new driveshafts for your truck. You would also have to modify the transfercase shift linkage.
By getting a dodge 4wd married trasnmission and transfercase, you will only have to have 2 driveshafts made. Also the shifters for the transmission and the transfercase should be pretty well lined up.
If you use the 2wd dodge transmission, you can use any year. If going for the 4wd transmission and transfercase, I believe you would need to use 94-97. The reason for this is for the mechanical speedometer. I am not familiar with the tranfercases that were used with the NV4500, so I really can't say how the speedo would hook up.
On my 1959 gmc 2wd, I used the 94-97 2wd NV4500 as that one is the easiest to hook the speedo up to. If you use a 2wd transmission, you would hook the speedo up to the transfercase.
Ok, enough blabbering... I really don't know the ins and outs of this swap... I'm sure these guys will be able to help. Good website too.
http://www.high-impact.net/transmission_and_gear/nv4500.htm
