How big a difference are they talking about? Is the problem a difference in the width of your boards or the width of your bed strips? Could your bed be from a different year?

I assume the problem is that your bed strips are too wide compared to what they have on file? If so, perhaps you could rout a wider groove in each board?

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)