I have recently ordered a new 2021 GMC 3500HD standard box (OEM puck system) and am considering getting an auto slider hitch. My current truck is a 2017 F250 SB with a manual Reese slider and we have a 2018 Reflection 337RLS that requires air bags to level the truck/trailer combination. I am considering the Pullrite Superglide and the Demco Hijacker. My concern is the 3500HD (12,100 lbs. GVWR) will sit up higher and potentially have a nose high trailer and/or low rail/trailer clearance. Both hitch types will require an adapter to connect to the OEM puck system, which raises the hitch that much higher. This concerns me since the Pullrite has no hitch height adjustment, but the Demco has a 2.75" adjustment range.

Is there anyone out there pulling a 337RLS with either of these hitches with a 2020 or 2021 GMC 3500HD? If so, do you have any unlevel/clearance issues?

Thanks very much for your input.