In the case of the 27RLS (8,600lb GVWR) and a GM 1500, it may boil down to your personal TV/TT loading habits. A GM 1500 properly configured may be doable and be within associated weight specifications, but IMO only under conservative TV/TT loading conditions.
I believe you may find that a 3/4 ton truck's added payload capacity would be better suited for the 27RLS under heavier loaded TV/TT conditions.
2016 GM 2500HD 6.0L/4.10
2005 Jayco Eagle 278FBS
Reese HP Dual Cam
Putnam Class V