8 3/4 Help and Opinions?

At the minimum, I'd upgrade to the chrysler 7290 joint. Hopefully you don't plan on racing the car with slicks--even with the 1350 joint, 4 speeds are brutal on 8 3/4" rears!

I upgrade most of my customer's to a new driveshaft with 1350 joints, or I atleast recommend it. Regardless if you go to the 7290 or 1350, spend the money and get a GOOD pinion yoke--one with u-bolts to retain the u-joint instead of the conventional u-joint straps. The straps are a very common failure point!

For what it's worth, I used an aluminum case 8 3/4" & 7290 joint in my old car with a transbrake. It left hard with a 1.38 best 60' time.

As far as the solid pinion spacer--it is an aftermarket part offered only for the 489 case to eliminate the crush sleeve (the pinion nut can back off, with the crush sleeve). The 741 and 742 cases use pinion bearing preload shims--and they have nothing to do with pinion depth. You can swap the pinion yoke without worry. Just remember to replace the pinion seal, torque the nut to specified torque, and use red locktite on the pinion nut threads.

Hope this helps some.