Here is a picture of the rear differential of my 64 Valiant. /6 225 engine. Please help me understand what the 312 and 10 mean. I'm trying to figure out what I have here so that I can get the correct pinion seal and gasket. The rear end has 9 bolts and I beleive it is a 7.25 since I think that is what came stock in this car

Thanks.

James.

As far as I know if it has nine bolts it is a 7 1/4.

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I don't think they every put anything else but 7.25" on /6 cars. Heck I've even seen a 7 1/4" behind a 318/727 combo even so I doubt they would put anything bigger behind a slant.

for the most part, like the early 60's cars should only get the 7 1/4", but with the advent of 'heavy duty' packages in the late A-body run some 73-76 /6 packages could have 8 1/4" behind them stock (I should know, I have a 225 /6 3spd manual floor shift, front disk brakes and a 3.21 8 1/4" rear 1974 Duster...)


just an FYI on slants and rears, that car should have a 7 1/4" rear....

-D.Idiot

I have an 8 3/4" with my slant six car, a Dart GT, as far as I know the axle original to the car. I'd never seen anything except the 7 1/4".

Tim,
Whoa interesting... I wonder how that 8 3/4" got there. You have the buildsheet for the car?

James, you've got the right idea. Look on the other side of the center section, on the lower webbing there it may say 22 or 25. It's probably a Dana 22 or 25. We call it a 7-1/4" axle.
Pierre and Tim, around '67 they started putting 8-3/4" axles in V8 4spd applications, and it also was available in HD fleet or taxi apps(which may include sl/6 apps).

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'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

My service manual says that the gear ratio is stamped somewhere on the case.

When I was changing my seals on my 7 1/4, I found markings like the ones in the original post, but nothing like a gear ratio.

Could these be code for something? Does anyone know what they mean?

And most importantly (for me) where would I find the ration stamped or engraved on the case.

Thanks,

John

After further cleaning and scraping the differential case, I found more markings. As Killin5 indicated, there is indeed a stamping of the gear ratios. The gear ratio was stamped on the passenger side of the differential facing the pavement. The ratio is 2.93. Also on the passenger side, facing the rear of the car is the casting number 02070051. I did a search for rear ID sites and found this interesting site you guys might want to check out.

http://www.geocities.com/motorcity/shop/3978/rear.html

This site lists my casting number so I'm now pretty sure the thing is the original 7.25. I was worried that someone might have swapped out the original at some point. I have no build sheet and Chrysler Historical Society wants like $45 for it. I suppose it is worth it one day.

I also have another problem getting the nut loose. See this thread

http://www.slantsix.org/forum/viewtopic ... 5026#25026



Thanks

James.

Pierre, my car is a '67 GT convertible. I have seen others like mine with the 8 3/4". I believe this is a 742 center section. This car also has K-H front disk brakes. It is a 225 car, I don't think anythng has been changed.

Back in the early 80s, a buddy of mine had a '65 Dart GT, 273-4, 4 spd, 8 3/4 rear w/2.94 Sure Grip. The 8 3/4 was in it when he got it. We always thought it was the original rear and at the time it didn't matter if it was or wasn't, so we never looked real close to verify it. This was still a nice car when sold, 10 years latter I came across it in a junk yard completely stripped.

Cecil

The late sixties and early seventies car makers were out to please as many customers as possible, while rare, some /6 A-bodies did come factory equiped with the 8 3/4. My 741 with 2.76 gears came from a '70
4-door Dart (equiped with the tow-package). I personally seen only one other, again '71 4-door w/tow-package. I don't have a build sheet, but I, for one, am certain these were original.

For the guys with the 8 3/4" and th 225,
Im asuming it came with a 904 as well? Can you get me a measurment on driveshaft length?

If you go from a 7 1/4 to an 8 3/4, you'll need to shorten your driveshaft about 2 1/4"

Depending on the yoke on the 8 3/4, the stock Ujoint may fit. Mine did.

I wrote up my swap on my site.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

My '72 Satellite has an 8 3/4. A friends '72 has a 318 with an 8 1/4. Mine is an early build '72 made in Windsor, his a late build made in St Louis. Strange....At least I never have to worry about the axle!