You'll find that lots of people go way over, but you need to go in with eyes open.
Newer campers aren't made for 20 year old trucks. Sure, it's possible to carry them, but most truck brands have radically increased GVWR compared to even 10 years ago. Newer drws, have up to 4000 more GVWR with even newer SRW having higher GVWR than your truck. Yes the trucks weigh more, too.
There are lots of discussions here that usually come down to don't go over your axle ratings and tire ratings, but that doesn't consider potential braking issues.
In any case, I'd say your camper sheet weight is probably close. How far you go over is up to you and the weight police.
'10 Ford F-450, 6.4, 4.30, 4x4, 14,500 GVWR, '06 Host Rainer 950 DS, Torklift Talon tiedowns, Glow Steps, and Fastguns. Bilstein 4600s, Firestone Bags, Toyo M655 Gs, Curt front hitch, Energy Suspension bump stops.
NRA Life Member, CCA Life Member