Which chain for my np203

[mofugly13]

I think the chain in my np203 has stretched. It has a part time kit. When in 4wd and I put a load on it I get a 'bang' from underneath the vehicle every few rev's of the tires. I don't know when I'll get around to changing it, but would like to have a replacement on hand for when a block of free time pops up. I know there are two different chains, I think the difference is in the width and 'pitch'? There's 1/2" and 3/8" pitch. . Anyhow, how do I tell which one I have, do I need to pull the front output? What's the easiest way to find out, so that I can have the right chain on hand when the time comes?

 

[Ryan B.]

Put a 205 in it?
th350-np203's are pretty abundant in the junkyards.

 

[Cricket]

As far as I know the only difference is width, I had the skinny chain and IIRC pre-77 had the thicker 2.5" chain. 77-79 had the thinner 2" chain. You could probably access it through the PTO cover. (That little square cover on the driver's side) It's in a good spot.

 

[mofugly13]

If I put a 205 in it I'd have to change my driveshafts. I wanna rebuild the 203, so that down the road I'll find a 205 and use the 'recently rebuilt' 203 range box for a doubler setup. I just want the 203 to work right, and worry about driveline changes down the road when cash is more abundant.