Hey guys, I picked up a used 2006 Colorado rear axle Friday. It is a 2WD, Z85 (standard suspension), GT4 (3.73/1 ratio), G80 (Eaton locking differential), drum brake-equipped unit. It is 60.75" wide WMS to WMS (wheel-mounting surface). I don't know about the differences in the 4WD or Z71 options. I will take some spring-perch dimensions and post them. FYI, an original AD 16" wheel looks like it will fit over the drums (mine are a little crusty, hard to tell without some cleanup), more info here to come also. They are available in at least 3:42, 3:73, and 4:10. This may be an option for those who change to an open driveline, and retain stock, 6-lug wheels.
Nate, I paid $350 for the rear end complete with brakes. I have seen them listed for as much as $875.00 on the salvage yard search engine. Speaking of which, here it is: http://www.car-part.com you simply follow the prompts, and a listing of all items which meet your search criteria will be displayed. This is for late-model vehicles, but a valuable tool nonetheless!
Thanx ! Back in the day , a " Colorado " truck axle meant it had 4.11 gears and so they were much sought after for Hot Rods . Not so good for 6 Banger work trucks @ sea level as they'd wind up to fast & run out of breath on the open highway by 50 MPH or so . Stupid question : is " Colorado " a Chevy model designation now ? . TIA ,