I would assume the frame flex is one outside rail moving with respect to the other, not the bending of the actual rail channel. I think the fit of the rivets degrade over time and allow more of this movement.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!