Originally posted by unstable
Question of the day is...
Assuming someone did indeed install the kit into the NP203 that is currently installed in the truck...and I put a new NP203 in (without the kit)---will I encounter any problems?
I ran my 1978 GMC with full time for 4 years with the full time transfer case in it's normal intended from the factory full time state.
The best mileage I got out of it was when I swapped in a 305 I had rebuilt, it gave me 18 mpg highway with 3.55 gears and 31/10.5/15 tires and a full load.
The NP-203 full time transfer case has an internal differential that allows front and rear drivelines to operate at all times without the typical binding and subsequent bucking while turning the truck on pavement, UNTIL you shift the lever into the HI-LOCK position which only locks the transfer cases' internal differential.
I certainly wouldn't hesitate to run the full time case as you will probably never realistically get much more mileage out of it, looking at one of these trucks with ANY of the NP-203/205/208 transfer cases in it from behind while travelling on the road you will notice the front driveline rotating even if equipped with locking hubs disengaged.
The only thing about the full time 203 is if the front axle is equipped with locking hubs, and you disengage them the 203's internal differential will send all power to the front axle and you won't go anywhere, simply locking the cases differential by shifting into HI-LOCK will remedy this situation.