I've got a question about my truck, since I've heard many opinions on the matter I thought I post hoping to shed some light on the situation.  First off, I'll give the details of my truck.  I've got a 1978 Chevy fullsize 1/2 ton 4x4 with a big block 454, 350 tranny, and 203 transfer case with limited slips both front and rear.  Its got a modest 3" suspension lift along with some fender trimming.  I currently run 33" TSL Swampers, but I could easily fit 35" or 36" rubber on it.

When I bought my truck, it had after market locking hubs installed.  However it does not have the part time conversion kit installed in the 203 transfer case (I've heard installing the part time kit just creates a weak point in an already pretty strong transfer case, so I have no intentions of installing the kit).  Now to my question, as I'm sure you are aware of, when running the old 203 cases and lockout hubs, if you set the hubs to "free" and have the case in "2 High", you don't go any where when you hit the gas, you have to switch to "4 High" if you want to move.  (This isn't my first truck with a 203 and lockouts, so I am fairly familiar with this situation).  However if you run the hubs in "Lock", you can then drive around in either "2 High" or "4 High".

So, my question is, for daily driving purposes is it better to leave the hubs in "Lock" and drive around in "2 High" or would it be better to leave the hubs set to "Free" and be forced to drive around in "4 High" all the time?  It seems to me like driving around in "4 High" and hubs to "Free" wouldn't be the best choice, but I'm unsure on the situation.  From the factory, it didn't come with any type of lockout hubs so essentially it would be like the hubs were in "Lock" all the time, so maybe that is the best route since that is more of a factory default configuration?

Any help would be appreciated, I've heard many so called "experts on off-road" recommend both ways, so I'd just like to get some info right from the horses mouth on the matter.

Thanks for your time!  

I have a '73 Blazer (SB 350, TH350, NP203), but I haven't installed a part time kit or hubs.  My t-case doesn't have a 2WD High gear, so first off I'm wondering if that really is a 203 case.  Unlocking the hubs and running in 4-Loc will run 2WD but the front driveshafts and axleshafts will still be turning.  My advice would be to run in 4 High all the time with hubs locked, if you are against installing the part time kit.  I drive my truck to school everyday, and never take it out of 4 High unless I go offroad.  Other than some slight slippage under hard acceleration, I haven't had any problems.  

The transfer cas shift possitions on a NP203 (from lever back to forward) are Hi-Loc,Hi,N,Low,Low-Loc.  The NP205 shift possitions are 4-High,2-High,N,4-Low.  Make sure your case is actually a NP203, if it is I would keep the hubs locked and run the transfer case in Hi unless you really need to lock it in or need low.  I have owned a 1976 1/2 ton full time (NP203) for almost 20 years, and a 1978 Blazer with the NP203; I also have trucks with the NP205, NP208, and NP241.  I only lock the transfer case in when needed.  

Its definitely a 203.  I just sometimes refer to "Hi-Loc" as "4-High" and regular "Hi" as "2-High".  More of my friends seem to understand what I'm talking about if I use the term 2-High or 4-High, since that is what they are used to hearing so I have gotten in the habit of using those terms.

My old 76 Chevy had a 203 with lockout hubs and I left them locked in and drove the truck in "Hi", and never seemed to have any problems for the life of the truck.

I'm sure thats what I will do with my 78 now, since thats more how the truck would be run out of the factory since it didn't ship with lockout hubs.

Honestly, why so many people put lockout hubs on trucks with a 203 seems kind of pointless, and remains a mystery to me.  If you don't install the part time conversion kit in the 203, you really aren't gaining anything at all by installing lockouts, but for whatever reason it seems the majority of old Chevy trucks I run across all have the lockout hubs installed.

Anyway, thanks for the tips guys, I appreciate the feedback!  

Just a note. I had myself a 76 chevy and installed the conversion kit and had not a trouble with it. And I abused that truck to no end. Then when you are in 2 wheel your hole frontend is not turning which is not so much wear and tear and better gas milage  

I recently bought a 77 chevy all time 4X4. It has after market lock out hubs on it. Set it to free didn't move. Talked to a mechanic buddy said it was normal. He thought the reason someone would put the after market lockout hubs without the transfer case conversion was because they were alot cheaper than replacing actual all time hubs that went bad. Makes sense i guess.  

i had a 79 wagoneer and it was all time 4x4.  it mostly pulls from the front.  the transfercase lever had 4hi, 4lo, and 2hi and a all lock swith in the glove box.  i put manual hubs because the price for the originals were somewere arond $250 to $300, which the manual were about 60.  that was my reason for the manual which probly was most peoples reason.  i left them locked all the time.  

im running a 203 with the conversion with a 454 for power plant. no problems here. i love thr ol 203, except for duing tranny work and having to remove the transfer case. it can get heavy  

truckin66:
I recently bought a 77 chevy all time 4X4. It has after market lock out hubs on it. Set it to free didn't move. Talked to a mechanic buddy said it was normal. He thought the reason someone would put the after market lockout hubs without the transfer case conversion was because they were alot cheaper than replacing actual all time hubs that went bad. Makes sense i guess.

You need to run Tcase in lock mode with hubs in free if you want to drive it. Front drive shaft will turn but no power is applied to wheels. For what it is worth, full time is a asset not a handicap off road. The only "bad" thing about it is that is uses about 10% or so more fuel.  

ive got a 78 full size blazer with a 203  i put a gear conversion in it so i could run in true two wheel drive. the kit is worth it.. i run 35s with 4 inch suspention and 2 inch body.. i run it harder than my 73 k-20 and have never had a problem with it the conversion kit comes from nash.. check it out.. youll be glad you did.. better mileage, less wear on stuff and in my mind tougher than the old chain drive  

I have a fulltime 4x4 truck, a old J20 Jeep that I have owned for over 22 years now. I am really7 glad it was fulltime for what I used it for because it is superior of road. I actually needed to lock it maybe a half a dozen times in its life. The rest of the time is was unlocked and with diff between axle the torque steering and axle/steering wheel whip is greatly reduced. You can get some really nice launches in every day driving on dry or wet pavement or gravel too all the time. Another plus is that you can safely use low range on a hard surface if you want to, for as long as you want to too! Back around 76, GM set a Guinness Book world record when they towed a 747 for about 2 hrs with a stock 3/4 ton P/U with fulltime 4x4 drive and a automatic. At one time they even broke the towing speed limit too.  

the 203 Transfer case is a "all time" 4 wheel drive
but its truely only in 4 wheel drive if its in hi or low lock

other then that it is front wheel drive
so yes you would have to have the lockers on for you to move in high or low
but my advise is to take out the lockers so its always locked  

so a chevy is front wheel drive unless it is in 4 lock or 2 lock  

The NP 203 in my opinion is a large heavy boat anchor with alot of week points. First week point is the chain drive in the main housing. If you are running any real horsepower, it can stretch and break or throw the chain. The tail housing on the NP 203 houses a gear set very much like an open differential. When the case is not locked to 4 LOW or HIGH it will tranfer power to the path of least resistance. So if there are locking hubs put in place and they are unlocked then it will spin they front axles and go no where. If you plan on keeping the truck and want to keep it as your personal project I would suggest swapping out the NP 203, but dont throw it away. It can be used for a "Doubler" project later down the road.  

jspalinger:
The NP 203 in my opinion is a large heavy boat anchor with alot of week points. First week point is the chain drive in the main housing. If you are running any real horsepower, it can stretch and break or throw the chain. The tail housing on the NP 203 houses a gear set very much like an open differential. When the case is not locked to 4 LOW or HIGH it will tranfer power to the path of least resistance. So if there are locking hubs put in place and they are unlocked then it will spin they front axles and go no where. If you plan on keeping the truck and want to keep it as your personal project I would suggest swapping out the NP 203, but dont throw it away. It can be used for a "Doubler" project later down the road.

There is nothing wrong with the design of a 203. It is quite strong. Where a lot of them failed in the past is because many never service them at all or not properly. It does require regular oil changes for long life and it requires NON DETERGENT 30 weight oil, not 10w40 as some recommend. There is two reasons for the oil selection, first non detergent foams much less in Tcase and lubes better because of it and second straight weight oil has no VI in it which actually reduces film strength. As far as torque capacity, it will handle more than any modern chain driven case used in SUV's as chain is massive. The planetary reduction unit is stronger than the  non planetary one in 205 and quieter too The few "bad" things about it is that it does use more fuel and it is VERY heavy. BTW, one poster above wrongly mentioned that it is only in 4x4 when locked but this is not true because it is always in 4x4 and when unlock it can do nothing less than send same torque to both axles (no more no less) and that is 4x4 drive. Locking it just lets you send more to one axle than other. Also, I have a old J20 jeep with fulltime and I plowed snow and towed with it for many years and never had 2 cents of trouble with Tcase (I did change fluid in it regularly) I found fulltime to be superior plowing snow in handling and smoothness of steering in tight power turn and rarely ever needed to lock it. Generaly people than knock fulltime have never truely lived with it for a while and properly maintained it.