8 3/4" rears and small bolt disk brakes are expensive and very hard to find anymore
a more economical solution is to look for any late A-body with an 8 1/4 rear and matching big bolt front disks, the 8 1/4 rear is plenty strong enough for anything short of an all out race car, and the big 5X4.5" bolt pattern gives you many more choices when it comes to wheels
