8 3/4 Rear end question - 72 RR

[Bagherra]

Hey all,
I have my eye on a couple of 4.10 sure-grip differentials right now.

My question is...
If I get a 8 3/4 sure-grip differential will it fit in any 8 3/4 rear or do I have to worry about a 489 going in a 489, etc.?

...also when someone refers to a 4.10 489 case that means this (see pic below)...? Sorry if these questions seem dumb, I'm completely wet around the ears when it comes to rear ends.

[dwc43]

489 is the last digits from the casting number stamped in to the case. Some cases use a straight pinion some a tappered pinion etc.etc. The casting number is needed to match the right gear to the right case. The suregrip carrier can be swapped between every case no matter what the number is. Missed you at the car show. THere was several gears and sure grips there for sale.

[Bagherra]

Originally posted by dwc43
489 is the last digits from the casting number stamped in to the case. Some cases use a straight pinion some a tappered pinion etc.etc. The casting number is needed to match the right gear to the right case. The suregrip carrier can be swapped between every case no matter what the number is. Missed you at the car show. THere was several gears and sure grips there for sale.

Thanks, just so I get the terminology straight in my head...
Case = the pic I show above
Carrier = what houses the pumpkin (or case)

I get confused sometimes.

As far as the show was concerned I couldn't make it since between working on the car and home - I did not have any free time for fun.

[Mr.Sixpack]

Yes you can use any pumpkin like 41, 42 or 89 and fit it to your rear without any problems.
So get a fresh 4.10 with 489 case and smoke those tires.

Good luck

[dwc43]

Originally posted by Bagherra


Thanks, just so I get the terminology straight in my head...
Case = the pic I show above
Carrier = what houses the pumpkin (or case)

I get confused sometimes.

As far as the show was concerned I couldn't make it since between working on the car and home - I did not have any free time for fun.

The case is the case of course and the carrier is the suregrip or open diff part. Sorry you missed the show, but I understand. It was good. Plenty of hemi cars a Superbird and a few parts.