This handy drilling guide is used to mark the hole centers when converting the wheel stud bolt pattern on Classic Bronco spare tire carriers measuring 5 on 5.50 inch bolt circle diameter (B.C.D.) to convert to 8 bolt on 170mm bolt circle diameter.
Simply place the drilling guide over the stock 1/2 inch diameter wheel studs, then use the small holes a punch to mark the exact centers of the new 8 bolt on 170mm B.C.D. Drill your spare tire carrier to your new desired wheel stud size.
