Engine swap thread from He11

If you need it up and running quick I'd be tempted to leave the rear axle as is for now, and your old driveshaft should work. After you get the new engine fixed up, then you can swap the axle as another project. I don't know if the emergency brake cables are different between your present axle and an 8 3/4, but you'll have to deal with bleeding the brakes, etc.