I've got a set of very nice 1/4" aluminum wheel spacers that were made for me by Skulte Performance. They are drilled for both Ford and Chevy bolt patterns (5 on 4.5 and 5 on 4.75"). These are brand new, never installed. I ordered them for a 99 Mustang GT with IRS (the wheels set too far in), but they never made it on the car.
These retail for $79 a pair plus freight.
$70 shipped OBO