1978 9.25 interchange

[TroyCo]

Found a 9.25 axle from a 1978 New Yorker, just wondering if it will interchange with my '66 Polara?

 

[traintech55]

You need to get under your car and measure the distance from backing plate to the other side and the distance between the spring mounts. The ones on the new axle are different, but you can get the bushing to make it work.

 

[1970FuryConv]

That axle is too wide.
You need 1965-1969 rear, which has 60.7" wheel track.

 

[TroyCo]

Thanks.

 

[1970FuryConv]

8.75 rear with 742 center section would be ideal. Good luck!

 

[TroyCo]

I have all the parts I need to build one. Either a 741 or 742. I just saw this other rear that was already assembled for cheap and it got me to thinking of other options.

 

[1970FuryConv]

I have all the parts I need to build one. Either a 741 or 742. I just saw this other rear that was already assembled for cheap and it got me to thinking of other options.

Awesome! Are the center sections already assembled? What gear ratio are you going to run?

 

[TroyCo]

I have two 742 open diffs with 2.76 gears. I have a 3.23 ring & pinion for either one of those. I also have two 741 diffs, one is a 3.23 open and the other is a 2.94 with a sure grip. Not sure which one of those carriers is getting the sure grip though. It all depends which has the least wear.

 

[1970FuryConv]

Keep us posted. I have rebuilt motors and automatic transmissions, but I've never learned to rebuild a rear end. Always like learning something new.

 

[TroyCo]

I've never attempted a differential either. Should be interesting.