What rearend is this?

[bordin34]

I found this on craigslist and its listed as a sure-grip 9-1/4" from a 1977 New Yorker. I thought the cover on should be more of an octagon than whats in the picture. Can anyone confirm it is a 9-1/4" before I drive to find out. It will be going into my 73 Charger. Also is the bolt pattern 5x4.5 and not the larger imperial pattern?
Thanks

[tsmithae]

Certainly doesn't look like a 9 1/4 to me... more of and 8 1/4.

[70 sublime]

Being from a New Yorker maybe you should find out how wide it is compared to your Charger

[bordin34]

It should only be around 1.5" wider from drum to drum and the same perch to perch.
It isnt a 8-1/4" because the one I posted is 12 bolts, 8-1/4 is 10 bolts.
Its also only $100.

[tsmithae]

I was just counting bolts and you are correct, it has two too many bolts....

[bordin34]

I picked up the rear yesterday. I would say it was worth it for $100. I took off the cover and it had a weird fuzzy rust all over it. The consistency of it was like someone poured bread crumbs onto the diff. I could take my finger and wipe it all away down to clean metal. I sprayed PB blaster all over it and nearly all the rust is gone now.

[GreenMachine]

Looks like a 9 1/4 sure grip to me.

[A383Wing]

with all that rust, maybe a look at the bearings would be in order?

[bordin34]

Almost all the rust came off just from spraying it with PB blaster. However it looks like I will at least need to replace the ring and pinion, there is a small sliver on the coast side of the ring gear missing on every tooth.

[A383Wing]

bet there is a lot of backlash also

[Sublime/Sixpack]

Are you sure it's not sawdust in there?  Years ago I heard that some people used to do that to make a noisy rear end run quiet so they could sell the car.

[bordin34]

I'm not sure I didnt take a magnet to it but I am pretty sure it is ferrous.
I already found some used 3.55 gearsets for under $100 and Jeep Liberty disc brake setups for around $150 so I can convert it to discs. I am thinking I can have a decently strong diff with disc brakes for under $500 when all is said and done.