New Process 203 chain

[CSHADES]

Last winter the old 77 plow truck was clanking pretty bad in 4wd under a load. I pulled the rear driveshaft because it was shaking the truck pretty bad at 55mph. The shaft was very crusty and the slip joint was very worn. so the driveshaft place built me a new shaft which cured that problem. When I pulled the shaft I put the truck in hi lock to move it and figured out my clanking noises were coming from the transfer case, so we pulled the case out yesterday and pulled the tail shaft and covers off and had a look. the chain is very stretched and needs to be replaced. Anybody out there have any ideas where I may obtain a new chain? I have looked online and also called the drivetrain place here in town and have had no real luck. I know there has to be one out there, I did find a used trans and case on craigslist for $275 but my concern is if it is going to any better than what I have.