Have you tried calling Starcraft directly?
Fwiw my Land Cruiser is on a 2.5inch lift/35s and when our Coleman was at stock height I needed about 6-7" of drop..Wound up getting an 8inch adjustable drop hitch..Now the axle is converted to a spring over and larger tires Im using about 4inches of hitch drop.
'17 Shadow Cruiser 240BHS
'08 Toyota Sequoia Platinum
‘07 NBS Silverado 2500 Dmax