It's a Colorado, my son had a 98 S-10 and I'd done the same rust around the spring mounts. We traded it too. Chevrolet could give these frames a dip and they would live forever! Can't sell cars that way though. It's a conspiracy!!!Is this an S10? My dad bought one new in 1998 and the bottom looked like the Titanic in no time! Eventually the frame got a huge hole near one of the rear leaf mounts and it got traded in. I think it was about 12 years old???
Another thing bad was always having to replace rotors on it. They would badly rust in 1-2 years time.
The makers don't want them to last. They make more money selling new. Parts these days are crap too. Exhaust pipe, mufflers, rotors, etc. Chinese metal??? Just made too thin??? I don't know?