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

looks like a 12 bolt 9 1/4 from a car to me.

perches are for axle on top of springs = car

pinion snubber = car

axle tubes swagers down to smaller end cups at backing plate = 9 1/4

cover has 12 bolts = 9 1/4

cant see wheel bolt pattern in pics but most likly 5 on 4.5

if it is 5 on 5.5 then you could swap in some 9 1/4 axles with 5 on 4.5 wbp

Axle I.D.



It would need to be narrowed to put into your Charger. I think its about 1 1/2" wider overall.

Thanks I saw the axle ID image already thats what prompted me to ask the question. In the image it shows the 9-1/4 being almost a perfect octagon. In the picture I posted it looks like one half the octagon is rounded.

It also looks like I should be able to just fit my tire and wheel package with this rear. I may need to roll the fenders a bit just to be totally safe.

All the 9 1/4 I've sen have tapered axle tubes(they step down about halfway the brakes backing plates), the 8 1/4 don't

Thanks. I know it is not an 8-1/4". I am trying to 100% confirm it is a 9-1/4"

Do the axle tubes step down? If not probally not a OEM Mopar 9 1/4 There is nothing wrong on the stock 8 1/4 rear end, the 8 1/4 rear ends work good

There is a step in the tube in the pic.

It is the older 9.25 cover, they were round and turned octogonish later but I don't remember the year they changed.

As a side note for you rear end gurus, I have a 9.25 rear with full floating axles out of a one ton, I actually have two of them, any one want to guess where they came from?

It wouldnt be possible to tell if it has the iso setup from this angle. The perches are very similar except for the height and center hole diameter.
My Charger currently has a 440 9.6:1 with a 60303 cam, and 440source heads with a 2.45 open 8-1/4" rearend. So anything in the rearend is an upgrade. Going from the 77 Chrysler brochure sure-grip was only available in the New Yorker with the 2.7 or 3.2 ratio. 2.4 would be special order and open.

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.

I had a 8 1/4 that looked sorta like that.

I used a pressure washer with some purple cleaner to flush it good and slowly turned it by hand to till the bearings were flushed good added oil and it is still up and going.

I would suggest pulling the axles and have a look at them to see if they are rusted and need a cleaning also.

After looking at it more I think I am going to replace the ring and pinion and all bearings.
There is a very small sliver about the size of a clipped thumb nail off the outside edge of the coast side of every tooth on the ring gear.

Look how thin that ring gear is, can't be much gear in that rear.

Dana 53?

It is a 9-1/4 that came out of a 1977 New Yorker parts car. The ratio is 2.7. I'll try to take a picture of the chipped gears and post it.

Here is the best picture I could get. Look at the sliver missing from the edge of the coast side. It is nearly identical on every tooth. Also as you can see nearly all the rust wiped right off.

If I were you I would cut my loses, the wrong rear end, not a popular design (but a decent one), needs gear set and bearings at a minimum, need to verify lug pattern, have to buy special offset wheels to center the tires correctly or get any size tire in the wheelwells. I think you are gonna spend a lot more money than if you just bought an 8.75, maybe the same money but you would have argueably a lesser rear end. Obviously it would have been a better decision before you spent the $100 but no reason at this point to continue to dump money into a bad idea.

I almost have to agree with mopar346. Yeah, your buy-in was cheap, but, how much are you going to end up spending to overhaul that? And you're going to have to weld on new perches too.

I've got a non-rusted version of that that's been sitting in my garage for YEARS because I can't give it away, yet, I can't bring myself to scrap it either.