I looked at a Chevelle that has rust through on the frame where the power steering unit and anti-sway bar mounts. Is there a replacement piece for this or do we just do some creative welding to fix this up?

Cut & weld in patches... but if it's rusty there, I'd be concerned about where else it might be rusty...

Ditto what Derek said

You can sometimes find frame horns on the web but I agree with the "other issues". Look for rusted, weak areas behind the front tires. The frames trap debris where the front "sub-frame" welds to the channels under the doors.

I drove to OK for a good frame for my GTO because of the very issue you referred too. The whole frame was toast....

If its that bad. I would be inclined to pass on it.

I did get under there as best as I could but I didn't want to get my Northstar Chevelle club shirt too dirty. If the guy does call me back I will also bring a jack for better inspection. I think I can get this one very cheap though.

I'd seriously consider going down south to pick up a completely solid car... the interior is way easier to replace than sheetmetal and a frame. You can probably find a completely solid Arizona/New Mexico rolling shell for $500 if you're willing to travel. Combine that with a rusty northern parts car for the interior and soft trim, and you can put together a car that's as solid as a brand new one for way cheap.

The body isn't too good either but if I could get that part of the frame welded up it would at least be a driver. Plus, if I get my other next Chevelle soon I would actually have 3 Chevelles so how cool is that!?!

If the body was solid and it was only the frame that was bad like on the 2dr you had I would say get it. With a bad frame and rust elsewhere you are getting a parts car to patch and drive around. Save the funds and wait for a better car that as Derek said only needs an interior or drivetrain. Having 3 Chevelles sounds great to the point of storage and upkeep comes into play. If you had storage, cash, time, skills, and equipment you would be good to go on this project.

Ah ... the voice of reason, thank you Dave. I also collect Hot Wheels.