I've got the same issue on a '52 3100 I recently purchased (Rear wheel well opening 1 1/4" lower than front and rear of running board 1" lower than front).
Terry
FYI, the wheel openings on AD trucks are NOT the same height front and rear. The front wheel openings are higher (presumably so the tire has room to steer), the rears lower. If you make the wheel openings the same height the truck will have a slight forward rake. The running board measurement is a good criterion for leveling. I usually put an angle finder on the horizontal part to measure my rake angle in degrees.
Okay DADS50, your turn...
