the 8.5 is smaller than the 9 3/8 housing obviously.. and it will take a lot of power, especially with the 90 up 31 spline axles, i guess i am saying its a little small in comparison.. not that i wouldnt use one myself if necessary.
that 85 Caprice wagon, if true would be a great source for rear end housings for these cars. wiki says the Caprice was the same basic design from 1980-90.
the wagons used the same housing till 96... some with rear discs too.. when i had the wagon i measured it up against the buick. the control arm mounting points are same distance apart on both housings. and the bolts are the same size. oh and police car caprice disc brakes bolt onto the 8.5. i just never had an opportunity arise to need to swap out rear from buick.
