nitro_rat
Lunchbox Lockers
What is the current drivetrain? 350, TH350, NP203 with a part time kit?
My vote if you really plan to use it is to snag a 700R4 and NP208 or NP241 out of an 80's vintage truck. You can even make a TBI 350 look almost just like the original carbureted motor. The fuel injection and overdrive will really help with driveability.
IMO a NP203 with a part time kit is a ticking time bomb. There are several different kinds of kits to disable the differential in the transfer case. The cheap ones have blocks that replace the differential side gears. The better ones replace the entire assembly with a blank shaft. The common denominator with all of them is that once the kit is installed the tailshaft bearings only get oil when the box is IN 4WD!!!
Here's a good article that shows the difference in the kits that are available:
All that said, I really like the way the full time case works as designed. You may pay a small penalty in mileage but it's worth in in my opinion. If you feel that you need a part-time case, I'd recommend that you swap in a part time case, be it the 205, 208, 241 or whatever.
Also with the 203, a factory service manual to adjust the shift linkage properly will address a lot of the complaints with this case!
Lots of guys bad mouth the 208 but it's fine for 90% of people and has a much deeper low range than the 203 (2.61:1 vs 2:1). The 241 is a little bit stronger and has more aftermarket support as far as slip yoke eliminator kits and lower ratio planets. It has a 2:72:1 ratio I believe.
While you're working on the drivetrain, I would suggest upgrading to a 9.5" 14 bolt semi-floater rear end. This will give more strength and weight carrying capacity. A unit from a 88-98 (GMT400) truck is best. The "heavy-half" and light 3/4 ton axles are 6 lug. Make sure you get a unit that is from a 4x4 truck as the 2wd variant is narrower by several inches. This will also let you move up to a 1410 u-joint on your driveshaft. If you get a steel shaft from the donor it can be cut down inexpensively to fit your K5.
I would recommend upgrading the front shafts and u-joints as they are a weak spot with the added weight of the camper. Aftermarket shafts and the newest version of the u-joint (don't know the number off hand but they changed it again when the JK Wranglers came out) but it's much stronger than the originals.
As far as driver comfort, the biggest thing for me is that the wipers and washers on these trucks suck big time! Detroit Speed now makes a modern windshield wiper conversion that is sweet. You get IIRC 7 speeds and an electric washer pump. HUGE upgrade and pretty much looks stock except for the wiper motor under the hood.
I'm sure there's more but that's my take from daily driving and wheeling these trucks my whole life...
My vote if you really plan to use it is to snag a 700R4 and NP208 or NP241 out of an 80's vintage truck. You can even make a TBI 350 look almost just like the original carbureted motor. The fuel injection and overdrive will really help with driveability.
IMO a NP203 with a part time kit is a ticking time bomb. There are several different kinds of kits to disable the differential in the transfer case. The cheap ones have blocks that replace the differential side gears. The better ones replace the entire assembly with a blank shaft. The common denominator with all of them is that once the kit is installed the tailshaft bearings only get oil when the box is IN 4WD!!!
Here's a good article that shows the difference in the kits that are available:
Mile Marker NP203 Part Time Kit
Mile Marker NP203 Part Time Kit I really liked Full-time 4wd on my 1975 Jimmy. Full-time 4wd worked great in poor weather conditions such as ice, snow, or heavy rain. This truck always felt solidly planted on the street but Full-time does have...
ck5.com
All that said, I really like the way the full time case works as designed. You may pay a small penalty in mileage but it's worth in in my opinion. If you feel that you need a part-time case, I'd recommend that you swap in a part time case, be it the 205, 208, 241 or whatever.
Also with the 203, a factory service manual to adjust the shift linkage properly will address a lot of the complaints with this case!
Lots of guys bad mouth the 208 but it's fine for 90% of people and has a much deeper low range than the 203 (2.61:1 vs 2:1). The 241 is a little bit stronger and has more aftermarket support as far as slip yoke eliminator kits and lower ratio planets. It has a 2:72:1 ratio I believe.
While you're working on the drivetrain, I would suggest upgrading to a 9.5" 14 bolt semi-floater rear end. This will give more strength and weight carrying capacity. A unit from a 88-98 (GMT400) truck is best. The "heavy-half" and light 3/4 ton axles are 6 lug. Make sure you get a unit that is from a 4x4 truck as the 2wd variant is narrower by several inches. This will also let you move up to a 1410 u-joint on your driveshaft. If you get a steel shaft from the donor it can be cut down inexpensively to fit your K5.
I would recommend upgrading the front shafts and u-joints as they are a weak spot with the added weight of the camper. Aftermarket shafts and the newest version of the u-joint (don't know the number off hand but they changed it again when the JK Wranglers came out) but it's much stronger than the originals.
As far as driver comfort, the biggest thing for me is that the wipers and washers on these trucks suck big time! Detroit Speed now makes a modern windshield wiper conversion that is sweet. You get IIRC 7 speeds and an electric washer pump. HUGE upgrade and pretty much looks stock except for the wiper motor under the hood.
I'm sure there's more but that's my take from daily driving and wheeling these trucks my whole life...