There were some changes that took place in mid 65 regarding the 7 1/4.
Chrysler refers to the gears as side gears and pinion gears.
Also the carrier is called a case in the parts catalog.
See 1965 parts catalog at mymopar.
Look at 3-06-5 side gear 2070023 fits 60 to mid 65
Side gear 2404194 fits mid 65 to 1976.
Scroll down to 3-07-1
Same with pinion gears.
Early gear 2070025
Late gear 2404195
Case also changed.
See 3-04-6
Early case 2070537
Late case 2404193
This is just from decades old memory but it seems like the newer 7 1/4 was slightly stronger than the earlier differential.
Rockauto listing maybe for the mid 65 and latter.
If you don't mind spending the money, the early gears to fit your carrier can be found on eBay or maybe a member can help.
Experts on the 7 1/4 please chime in.