As stated put the rears on the front. I have front 1" spacers with studs, no problems. These were bought off Ebay - they are sold for Corvettes - I turned them to fit our disks.
I believe that ANY CAR with tapered lugs (ours included) have LUGCENTRIC wheels - where the lugs "center" the wheel and yield 100% of the stress induced by the wheel.
For a HUBCENTRIC wheel, look at a Ford F150 - FLAT lugs, and the wheels have STEEL centers that fit tightly on the disk or drum.
Good luck finding anyone to
a) buy just rears.
b) sell just fronts.
