My neighbor has a 2500 ext cab 6.0 quadra steer they drive the wheels off of. Truck is beat to hell, has 300k on it, power steering pump is shot, fuel pump is going, cat is rattling, mirrors are broke out, interior is all but shot, a/c don't work, but the damn quadra steer still works just fine. When it quits running, I'm gunna need to snag it
Are you sure its an extended cab?
As far as I know, the quadrasteer pickup trucks only came in 2 flavors:
1500 extended cab/short bed half ton 6-lug (whether it was in the form of a sierra denali/6.0 or silverado/5.3)
1500HD/2500 crew cab/short bed 8-lug 6.0
Ive never seen an (8-lug) quadrasteer truck that was not a crew cab.