Your other mistake was buying a 'trunnion bar' style. In order to stay clear of the swing hitch locking pins, you will also want to go with a 'round bar' style, where each bar contains
a big "L" shaped curve to bring the horizontal portion of the bar closer to the ground where it attaches at the Head.
The big question with sizing for the TMs with swing hitch is, how much bar length do you need to clear the hitch - while staying "in front" of the LP Gas tanks, which are pretty tight to the A-frame (and will prevent you from clamping the stirrups that far back). My own WDH bars are 32" long, but my WDH was an after-market modification by the Dealer's Welder - not the TM original version.
The E-Z Lift 48053 might be a match.For mine, this would also be perfect:
http://www.etrailer.com/Weight-Distr...s/PS49583.html