THis is a DRW D70 in the back of my old K5 w/ stock offset H1 rims... and the width is perfect. The rearend is wider than a SRW rearend. This rearend was out of a 79 K30.
THere are other width dually rears... there may have been some narrower ones in some of the box trucks, etc... but if it is out of a DRW pickup, it is wider.