WANTED 3.23 Gear for 7 1/4 Rear

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BudW

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A great gear to use – but I’m not sure they ever installed any into an FMJ body. IF they did, it would be pretty hard to find (extremely rare).

http://www.ebay.com/itm/CHRYSLER-7-25-AXLE-RING-PINION-3-23-RATIO-C7-25-323-/182383515490?hash=item2a76e79762:g:Iz8AAOSwo4pYSu3g&vxp=mtr

http://www.ebay.com/itm/Yukon-Gear-Axle-YG-C7-25-321-Ring-And-Pinion-Gear-Set-/291730302848?hash=item43ec7b2780:g:5ecAAOSwbwlXBDoX&vxp=mtr
These were found on eBay.

I would also check with FABO and FBBO (For A Bodies Only and B bodies) for sale/parts wanted - for it would be a lot more likely to find 3.23 (or a 3.21) in one of those cars.

I am fairly sure – but not 100% sure, the ring and pinion gear set from ’60 all the way up to when Dakota’s quit using the 7¼” differential (‘89/90 or so) will fit OK into a FMJ.
The differential carrier and axles might not fit (more limited upon fitting into an FMJ).

Recommendation number 1: You might want to consider adding limited slip at same time.

Recommendation number 2: Replace all of the differential bearings when you have it apart - and use quality parts (don't skimp on bearings). Some differential shops might not do the repairs without replacing all of the bearings.

Recommendation number 3: if there is a possibility, you might be using/making more power than a 318 2-bbl will produce, sometime during the cars life, you might want to consider finding an 8¼” differential - first. Parts are more available and less likely to leave its guts behind the car the first time you punch it.

If no plans more than a stock /6 or 318 2-bbl, then your plan of gears may be all you need (and a corresponding speedometer gear replacement to keep speedometer/odometer correct.
BudW
 

Rifleshooter

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A great gear to use – but I’m not sure they ever installed any into an FMJ body. IF they did, it would be pretty hard to find (extremely rare).

http://www.ebay.com/itm/CHRYSLER-7-25-AXLE-RING-PINION-3-23-RATIO-C7-25-323-/182383515490?hash=item2a76e79762:g:Iz8AAOSwo4pYSu3g&vxp=mtr

http://www.ebay.com/itm/Yukon-Gear-Axle-YG-C7-25-321-Ring-And-Pinion-Gear-Set-/291730302848?hash=item43ec7b2780:g:5ecAAOSwbwlXBDoX&vxp=mtr
These were found on eBay.

I would also check with FABO and FBBO (For A Bodies Only and B bodies) for sale/parts wanted - for it would be a lot more likely to find 3.23 (or a 3.21) in one of those cars.

I am fairly sure – but not 100% sure, the ring and pinion gear set from ’60 all the way up to when Dakota’s quit using the 7¼” differential (‘89/90 or so) will fit OK into a FMJ.
The differential carrier and axles might not fit (more limited upon fitting into an FMJ).

Recommendation number 1: You might want to consider adding limited slip at same time.

Recommendation number 2: Replace all of the differential bearings when you have it apart - and use quality parts (don't skimp on bearings). Some differential shops might not do the repairs without replacing all of the bearings.

Recommendation number 3: if there is a possibility, you might be using/making more power than a 318 2-bbl will produce, sometime during the cars life, you might want to consider finding an 8¼” differential - first. Parts are more available and less likely to leave its guts behind the car the first time you punch it.

If no plans more than a stock /6 or 318 2-bbl, then your plan of gears may be all you need (and a corresponding speedometer gear replacement to keep speedometer/odometer correct.
BudW
I am fully aware of the speedometer gear change, I will end up needing a 33 tooth plastic gear for plastic housing, but before I start looking for that I want to find a diff gear first as they're less common
 

BudW

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Finding a plastic 33 tooth gear may be fun.
I have seen hundreds of speedometer gears (not quite thousands – but close) and don’t recall ever seeing a 33 tooth plastic gear before.

The older metal/plastic gears, yes (and even have one for my car, for when I convert it to 3.23’s).
Plus, the 33 metal/plastic gear is also being repop’ed.

You might want to consider converting your car to the older style metal/plastic speedo gear system – if unable to find a plastic 33 tooth gear.

Otherwise, I agree, finding the ring and pinion is more important.

One more thing to consider: /6 equipped ’66-70 B-bodies came with (I believe – but not 100% certain) with 7¼” differentials – that will bolt right into an FMJ car. If unable to find a gear set – you might also try to find an assembly from the above mentioned car (with the smaller 7¼” shock plates).
BudW
 
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