HELP: 8 3/4 pumpkin swap

[FASTEDDIE1960]

hi folks,
i have a 1970 Roadrunner with an 8 3/4 rear axle that has 4;10 gears in it. I also have an older 1967 8 3/4 with 3.23 gears in it both are sure grip units but the early one has the buttons in it. Does anyone know if i can swap this older one into my Roadrunner? I am not sure about the axle lengths, just wondering if my 1970 axles would be too long (using the older pumpkin) with the buttons in the older pumpkin assy.. Any help greatly appreciated. Thanks

 

[dadsbee]

Better be buttons or spacers in the 70 unit as well, if it's still running taper bearings!

 

[hofferwood]

This may help.

Chrysler 8-3/4" Axle Guide

 

[PurpleBeeper]

Yes, you can use your ‘67 3.23’s directly into your ‘70 rear end. The only thing you need to do is check the rear end pinion u-joint size. There are 2 sizes, big and small. (Like 3-1/2” vs 3” or something like that?). You need to match up the back of your ‘70 driveshaft with the ‘67 rear end pinion. Both “big” - use big u-joint Both “small” - use small u-joint. One big & other small - use adapter u-joint (readily available)

 

[dadsbee]

If you're talking just swapping pumpkins, like I stated above!

 

[BeepBeepRR]

The buttons are removed for green bearings. Dadsbee is correct. If one has them and the other doesn't you may run into problems with the axels not seating in all the way if you have green bearings on your axels.