Is the base plate for a specific tow bar/brand? I just ran a search on Roadmaster's web site and they show brackets (their name for a baseplate) for that truck, although there's a note saying that, due to slight variations, you'd have to make a measurement or two to ensure you got the right one. Click here for their search page and scroll down.
One more caveat - it says "no diesel" for that truck, so presumably that means gas only, although I have no idea why.
First thank you for your response! I saw that yesterday and called Roadmaster. They (or who ever I talked to) claim that it?s not for 1 ton as well. I do not understand why because for 1997 ? ton and 1 ton chevy pick-up the frames are the same.