What Differential Do You Have in Your 1965 Barracuda?

from personal experience, i had a 65 dart, with 235/273, four speed car, dealer replaced 3 sets of gears in 7 1/4 , i changed to 8 3/4 then, a friend had a 65 cuda, same power train, he went through 11 7 1/4 rear ends, dealer told him no more free rearends, he had to change to a 8 3/4 rear end. i have the original letter from nhra, about the 8 3/4 in 65 a bodies, dated aug 1965, allowing 8 3/4 rear end usage . just food for thought