I've got a 78 K5,the shifter says 2 Loc & 4Loc instead of 2hi & 4high & 4low.Does this mean it's called all wheel drive?There was a guy told me thats what it means.I know when I took it in the mud,it spun all 4 wheels every time.

You have a NP203 full time transfer case. You may have a Milemarker part time kit installed.

It has superwinch lockouts on it.Are these good?

I broke 3 on my ford, but I'm abusive. :laughing: they seem to be okay on my old ladys rig though :grinpimp:

OK thanks.I've actually got this blazer for sale.But I've taken it out & tried it in the mud a couple of times.Best 4x4 I've ever had.

That transfer case is a full time 4wd case.
Inside the transfer case there are 4 spider gears just like an open diff.
Do you know how an open diff works?
Power can transfer from left to right wheels, ok.
The 203 T case does the same but front to back outputs.
In hi or low the spiders are in use allowing this tranfer of power. If the rear was in mud they could spin and all power would go to the rear only like a one legger rear end spinning one tire.
In high-loc and lo-loc the spiders are locked and the power is equal front and rear, to be used off road.
If you have lockouts in front and the T-case is stock, with the lock outs disengaged and the Tcase in hi or low, the front D shaft will just spin and the rear will get no power, you will only get power to the rear in either loc position, but the front dshaft, diff and axles will be spinning but not engaged at the hubs. Funky!
If it has been converted to a part time tcase, then hi and low are rear output only and either lock positions hi or lo, are both front and rear outputs together.
So you use the loc positions for wheeling with the hubs locked, and hi and low with hubs unlocked.
Got it?:shaking:

Is this a pretty good set up ?

Not desirable, but it works OK. People usually take this system out rather than put one in.
Has it been converted to part time?

I don't know.All I know is that it goes anywhere I take it.I took it to some old coal mine pits one day,was trying to get it stuck.Couldn't get it stuck.Works excellent.My wife was following me in my Z71 Silverado,because I have a winch on it (just in case) Truck wouldn't even go half way in.

if you cant get a truck stuck your not trying very hard. wher in illy are you im in terre haute IN, it right on the border of them.

I'm from Mt.Vernon,not real far.

If you have lockouts in front and the T-case is stock, with the lock outs disengaged and the Tcase in hi or low, the front D shaft will just spin and the rear will get no power, you will only get power to the rear in either loc position, but the front dshaft, diff and axles will be spinning but not engaged at the hubs. Funky!
If it has been converted to a part time tcase, then hi and low are rear output only and either lock positions hi or lo, are both front and rear outputs together.
So you use the loc positions for wheeling with the hubs locked, and hi and low with hubs unlocked.
Got it?:shaking:
Here is how you can tell! :confused:
Read much?