Rearend Indentification

[markmine]

Hey guys, i'm looking to rebuild the rearend in my 73 Roadrunner or pickup a rebuilt third member. I'm getting a bad vibration and the rearend is howling pretty loud. I believe the rearend is the stock 8.75. How do I know which case I have? I see 741 and 489 cases mentioned often, but I have no idea what they are? Appreciate any help, Thanks

 

[midnightrider1818]

you need to read the numbers stamped off the side of the case. they made a 741 i believe a 742 and the 489. the numbers are right in front of the yoke on the drivers side.

 

[Meep-Meep]

you need to read the numbers stamped off the side of the case. they made a 741 i believe a 742 and the 489. the numbers are right in front of the yoke on the drivers side.

Exactly right.

 

[wedge5]

Should be a 489. used 741 in late 50's-early60's 742 early to late 60's and 489 late 60's into the 70's. This is a rough history of the 8 3/4.

 

[Speedy Canuck]

I see 741 and 489 cases mentioned often, but I have no idea what they are?

The whole 741/742/489 rear end cases confused me as well. I wasn't really sure on what the differences between them were. This site helped explain everything for me:

http://www.usaimports.co.uk/Mopar_Tech_Pages/mopar_rear_ends.htm

(someone with more wisdom might want to give this a scan over and make sure all the info is kosher)