rearend 67 belvedere
 

my car has 8.75 rearend and a built 440, the previous owner has broken the gear 3 times he also informed they were not cheap gears as that was my first thought,he suggested i get a diffrent rear end "dana" not sure how much but i know they are expensive. does anyone have any other ideas besides the swap?
we broke the last one while test driving rolling around 30 and
stomped it, thanks in advance!

What brand are the gears? What ratio? What was the backspacing set to? Pinion bearing pre-load? What did the pattern look like?

If the gears are not setup proper and a good pattern is run, also if they are not broken in, you can damage them to the point of breaking them.

Chysler put the 8 3/4 rear behind 426 Hemi Automatics so they are quite stout. The Dana was used behind 4 speed 440s and 426 Hemis. Danas are heavier and more difficult to change gear ratios in. With the 8 3/4 it as simple as changing out the pumpkin where as the Dana 60 is like a GM and must be set up in the case every time you change gear ratios. Unless you have a high HP 4 speed, I would stay with the 8 3/4. I have had BB mopars since the 70s and have only had 1 problem with a 8 3/4 and that was bearing Noise(Howl).

what case is in the 8 3/4?
You may just have a weak one.
The 8 3/4 is strong enough, the dana is not needed.

What actually broke? What is the gear ratio? If the rear is set up right,you will snap an axle before breaking the gears.

thanks folks for the quick response i will get more info from previous owner on the gears and things tomorrow, sounds promising was not looking forward to the swap. thanks again for your help and patience!

found a axle stamped 741 and 3.23 gears and he toll me it was a 8 3/4 out of a 1964 belvedere is there such a thing