Are you using the stock Dana20 tracsfer case? If so you will need a conversion adapter from Advanced Adapters. The T-case will still be in the same location so you can use the stock cross brace. A 2" body lift makes it easier to mount the NP435 due to the shifter comming up under the dash but its not needed. Cut a large hole where the shifter will come thru so it can move forward and back so you can guide it onto the bell housing easily. The drivelines and exhaust should stay the same.
I used the NP435 with a NP205 so I had to change the exhaust route, modify the drivelines and make a custom cross brace.
The 435 is well worth the install process.