yo C,
I assume it is an NP203?
if so, most appear to install the conversion kit;
78bronco460 wrote;
"...Part-Time conversion kits (which just consist of new hubs) have always been touted as dramatically improving fuel mileage. I can't see it improving much. The engine is still putting power to the front differential and axle shafts, but not the wheels. So you're still using fuel to turn those components.
Part time kits for the 203 consist of more than hubs. They also include the part time kit for the transfer case. Depending on the kit, it's a different output shaft and some gear parts or else a set of segment gears and shims and misc parts to lock the differential section of the transfer case. If you ever take a 203 apart you'll see what I mean.
They do extend the life of front end components dramatically. Full time front driveline, diff, and front axleshafts are always engaged and turning whether they are engaged in the transfer case or not. Installing hubs alone doesn't change this unless you modify the transfer case with the part time kit..."
as buzzbronco09 wrote;
I think I have the original hubs from 78 with 203. I installed the part time conversion including the T-case. I don't know that I saw any real improvement in mileage but it did make it easier to turn and reduced the wear on the front end.
