These 4000 lb. pallet forks should have come with a stabilizer bar to limit side to side movement, the same as the smaller forks.
Also, the screw down rods (2 each fork) would be much better with a nut welded to the plate and the rod would then screw down into the nut. As it is the nut is attached to the screw rod, and as soon as the nut reaches the plate, the whole plate slips and slides sideways. This causes paint to be removed from the plate and constant repositioning of the plate while tightening.. This would not happen if the nut were attached to the plate as the rod would hold the nut and plate in place.