Bztguy,

Offset = distance from the mounting surface of the wheel to the centerline of the wheel. Farther outboard is (+) offset, inboard is (-) offset. Centerline directly over mounting surface is (0) offset.

Backspace = distance from inboard edge of the rim to the mounting surface of the wheel.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)