742 to 489 case - different axle splines?

[rmchrgr]

Currently my car has the original '68 742 case with a 3.23 clutch Sure Grip. I am planning to use a spare 489 case that currently has 4.30 gears and a cone Sure grip to swap in a set of 3.73 gears I got at Carlisle two weeks ago.

I have read that the axles may have different spline counts. I'm not totally sure on this so before I start buying stuff I want to confirm it. If I change to the later case will I need later 489 axles or will the original '68 742 axles work?

Thanks in advance.

- Greg

 

[RemCharger]

Same axles . The cone carriers have different side bearings than the real 'grips.

 

[Cranky]

Same axles . The cone carriers have different side bearings than the real 'grips.

For every 2 cone units that you send me I'll return to you a 'real' clutch type

Btw, ALL of the 72's and the 89's will interchange with with each other....iirc, it's the 71 case that uses a different size bearing on the carrier and that's only the ID of it.

 

[33 IMP]

All 8 3/4 have 30 spline axles, except aftermarket 35 spline axles used with spools.
You will have to pay attention to the block inside the carrier that provides the ability to adjust the axle end play.

 

[rmchrgr]

You will have to pay attention to the block inside the carrier that provides the ability to adjust the axle end play.

Are you referring to the thrust buttons?

 

[33 IMP]

Are you referring to the thrust buttons?

Yes.