My friend's using a Happijac framemount on his '05 w/9.5' Sixpac. He's taken that package on to some pretty rough/off camber roads in the Eastern Sierra and Anza Borrego that give me puckerbutt. That being said,I think I'd still trust a Torqlift system on that camper. I would think without centering guides you would get a little movement of camper though.
Happijac has worked great for me and the Northstar. I only used the ears on my '99 up front and it worked super on 33 Baja trips. That was on typical service roads. I can't comment on how it would have held up going east way into San Juanico. Sheet metal was heavier on the 2nd gens.
On the '07 and same camper,the Happijac framemount with supplied centering guides is working well. I get a little movement on the rear,which I minimize with side blocks. We're talking 3/8" or so.
2007 Dodge 2500 Regcab 4wd 5.9 CTD. G-56 , TC800 Northstar popup 24/7.