Spline?

I'm assuming that you have a 7 1/4 rear in your car at this time. If this is the case, I beleive that there are mid-70s 7 1/4 rears with the larger bolt pattern, but I am not sure if you can just swap out the axles. Someone should come along shortly and let you know for sure. Back to the 8 1/4 rear. From what I understand those rears will handle up to 400hp without problems. Mike