Might check in on some toyhauler websites or RV.net website with a large TH forum or our TH forum as some tow with lifted trucks.
A 60" bed height means making a sub frame lift for the trailer which makes for a taller trailer. Max height is 13' 6" on interstate roads but it can be much less on secondary state roads.
Some 6" lifts don't work well for carrying heavy loads especially suspension lifts. Do your home work on your lift manufacturer specs and referrals.
'03 Dodge 2500 Cummins HO 3.73 NV5600 Jacobs
'98 3500 DRW 454 4x4 4.10 crew cab
'97 Park Avanue RK 28' 2 slides