Dang! How many times did your truck roll over down the side of that hill? I didn't know there was any hills in Iowa. smile Are those side plates and bolts aftermarket? They may not be up to specs for stiffness. I try to reuse the original side plates and bolts when I change the pins because I have had problems similar to what you have.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission