HI I HAVE THE SAME PROBLEM AND MEASURED A TRUCK TO DAY A 1981 CHEVY G 30 BOX TRUCK WITH A 14,500 GVW IT HAS 5 LUG AKA 10 LUG WHEELS IN THE FRONT AND THEY MEASURE THE SAME AS MY 1954 CHEVY 6100 10 LUG TRUCK THE CENTER HOLE IS BIGGER ON THE 1981 G 30 BUT IT WILL GIVE YOU A 19.5 RIM SO IF YOU USE A 8R 19.5 THE TIRE WILL BE SKINNY