The 'bidding' as primary dirt contractors like Independent, Sukut in Calif use sideboards. Rental outfits (working for hourly pay) like Rentrak, Peed do not use sideboards.
Hitch Cracking: Reconditioning Stop Pads prevents damage to cushion hitch components. When stop pad are worn off the load cylinder bottoms out (steel-to-steel contact) transferring shock loads into the hitch castings. 621B dimension A: from center of horizontal pin to top of hitch stop block = 10.05" // dimension B: from center of H-link pin to bottom of hitch bracket stop block = 3.24" // dimension C: from center of horizontal pin to center of H-link lower bore = 13.30"
AND maintain correct ride height adjustment.
621 operator pay versus 631, 651 around here the pay rate is the same.