HallmarkChevy

I recently purchased a 2005 Hallmark Milner and put it on my 2011 Silverado 1500 crew cab. I expected the camper to fit without shimming, but realized when I was putting it on that the bed is curved at the back instead of being squared which does not allow the camper to sit on the bed. I wondered if anyone else has had this issue, and if so what they did. I would prefer to not shim the camper 4”, but if that’s is the solution that’s fine.