Pull one of the stock axles and count the splines, they probally are either 30 or 35 splines, the 18 and 23 splines where pre 1970
![](/ubbthreads/images/graemlins/scope.gif)
Either way you can have new car type axles made for your rear end just like what came in the original cars
![](/ubbthreads/images/graemlins/thumbs.gif)
Are you going to have it shorten to the stock width or narrower like a 1970 and earlier B body?
![](/ubbthreads/images/graemlins/scope.gif)
That width might fit better
![](/ubbthreads/images/graemlins/Twocents.gif)
Dana made those rear ends for all three car makers so they have parts to make any axle spline fit in the posi and open carriers
![](/ubbthreads/images/graemlins/scope.gif)
I have swapped the spider and side gears from 23 spline to 30 and 35 splinnes to use the bigger axles in cars and trucks
![](/ubbthreads/images/graemlins/thumbs.gif)