Where to find a RCSB frame?

[mruta1]

Hi everyone,
First time poster here. I am a high school auto shop teacher trying to get a student project off the ground. I have a '96 regular cab long bed that I would like to turn into a short bed. The truck has a zillion miles and we plan to basically rebuild the entire thing.

I did some research into shortening the frame and came to the conclusion that it would be much easier to swap frames rather than shorten a LWB.

I've been looking on Craigslist for what seems like forever with no luck. It just seems like no one ever parts these trucks out in my neck of the woods (Illinois).

Can anyone give me some pointers on where to find a shortbed frame?

Many thanks!