I bought a new ring and pinion advertised to fit a 7 1/4.

After removing the wax I found the ratio stamped at 3.21 not 3.23.

Now I'm thinking the advertisement was wrong & it's for an 8 1/4.

The ring gear has 2352938 part number stamped on it.

Can anyone confirm it's true identity before I tear down my 7 1/4 rear & it doesn't fit.

How do you measure a ring gear to check for 7 1/4?.....to the OD? to the center of the teeth?

Thanks.........Don

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

Measure across the OD of the ring gear...
DD

2852938 is for an 8 1/4" 3.21 ring gear

2352938 is an early part number almost early 60's-ish...is there some grime making the 285 a 235 maybe?

Time to break out the tape measure as Doc says.

-D.Idiot

Extreme O.D. of gear.....right out to tip of teeth...measures 8 5/8.

After closer scrutiny & more wax peeling the part number is a 2852938.

The pinion might give a hint if the ring gear doesn't with numbers:
35079 5 3 21 with a bearing stem dia of 1 1/2 dia. (definitely not 1 3/8!)
It has the MOPAR pentastar stamped in it

So based on the OD measurement I better not tear into my 7 1/4 yet!

My 65 parts manual shows numbers like 2467 326 for a Dart 3.23 pinion/gear set with or without sure grip......I wonder why they don't show individual ring gear numbers for the Dart/Valiant?

That same manual also shows the 65 B & C bodies to have an 8 3/4 with 3.23 ring gear 2070 816

Consequently based on the OD & part number this could be a later 8 1/4 or 8 3/4 ring gear?

Thanks for the responses........Don

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

According to the 1973 Parts Manual the stem size on 8 1/4" are 1 5/8" and 8 3/4" are 1 7/8"

Pinion # for a 3.21 is:3507915 or 3723044


So it looks like you have an OEM 3.21 set for an 8 1/4"


-D.Idiot

Summary: Based on the part numbers & ratio on both ring gear & pinion and your research it looks like a sure fire 3.21 ratio 8 1/4 with the smaller pinion stem diameter.

Thanks to your help I now know what to do....and it sure means for me....don't touch that 7 1/4 rear yet.

I altered the title so if someone is researching the same part numbers the'll have your research

Thanks..Don

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/