Turning a 1500 imto a 2500?

[CumminsBronco]

On the subject of frames, those of you that have Suburbans, what are the frame rail dimensions? My 97, which is a K1500 has frame rails that are 8" tall, 2 1/4" wide, and is 3/16" thick. That is just in front of the rear spring hanger bracket. Over the rear wheel the frame is 4 1/2" tall.
I had the opportunity to measure a 97 C2500 RCLB truck and its frame rails were the same dimensions.
Several weeks ago I was at a local junkyard that has approx 15 gmt400 s. I glanced under one K2500 Suburban, but it was an earlier model.....maybe a 92-94.....and its frame was much different than my 97. Its rails were not as tall and stepped down near the rear spring hanger bracket. I didn't have anything to measure with along that day. Guess I'll have to get back to get some measurements off of it in the near future.

 

[Masterelec2018]

I'd be surprised if they were the same thickness. Take a closer look at the donor, it should have reinforcement brackets at both leaf hangers.

I looked at the hangers today. The 1500 looks thicker and doesn't have an additional brace on the frame side. The 2500 had the brace but looks like a thinner material. There aslo different for the bed mounts. Sclb/ecsb and the rears are identical. The fronts have the additional brace. From what I can see