The ring and pinion is the weak link. Also the style of centersection. You can't fix it.
All housings flex and need to be strengthened, but my point is you'll still kill gearsets in an 8.75 no matter what you do.
The 9" has WAY more aftermarket support, but a Dana is cheaper...if you don't mind limited gear ratio choices and a little extra weight. These 2 each have their place depending on budget and the application.
At some point you will kill them sure, but there are guys going single digits GM 8.5s, Ford 8.8s, and GM 8.875s. I find it hard to believe that low 11s are the limit for an 8 3/4 ring and pinion based on the ring gear diameter alone.
A Dana is cheaper if you cut down a truck Dana and can get one for a good price - in some parts of the country its hard to find a truck Dana that people don’t think is worth $500. And you have to have the skill to narrow one or a shop around who can. I agree Dana 60 is the ultimate, but the aftermarket housing “band aid” might be pretty effective for a car thats not in the single digits at 3800 lbs. No one will ever know if they all go D60 or 9 inch Ford, just interested to know how much of a difference this makes.
If no one ran an aftermarket housing on a 9 inch I don’t think they would be in the conversation either, because their OEM housings are weak even with the built in crutch support.
