I agree with everyone on this but I think we need more info
1 are you using a fuel cell or a stock tank do you have room for the Dana
2 what about exhaust were will it go
3 how much power are you going to have to the rear wheels
4 how much does the car weigh and where is the weight. If the front is heavier than the back can you save weight in the front and help with traction Putting more weight in the back with a heavier rear axle will just slow you down.
I think there is a lot more going into this decision.
If you have good parts in a 8 3/4 meaning axles, bearings no crush washer and a nice tight clutch type posi unit they are plenty strong for an automatic but if you are running a stick with slicks and it’s tubed and you have a very wide tire the Dana maybe a better way to go
If I was going to run a Dana I would spend the extra on the Strange 60 it uses adjuster just like the 8 3/4 so you do have to worry about the thin shims walking out and you loosing the back lash setting. Also you can have it made to the correct width for your car and the wheel and tire size you want to run.
There’s my two cents but at least you have some more to think about so you can make the best decision for you and what you want to do
