The extra leaf doesn't provide lift, it provides less sag under heavier weights. That may sound counter-intuitive, but what it means is the the overload only comes into play when there is significant weight in the back, causing sag to the point the frame begins to rest on the overload. You'll still get the same amount of sag or squat in the rear as if there were no overload though because your camper will cause the rear to sag just enough that it doesn't touch the overloads. There is a couple of inches of sag before the overloads come into play, and you'll still get that amount of sag. So, you'll notice it, it will sag, you'll squat in the rear compared to the front with a leveling kit.
I fought this same issue. I put the camper on my F250 and it sat almost level, with the camper in the bed. I thought I'd like a little more lift in the front, a leveling kit. It gave me between 2" and 2.5" of lift in the front, which ended up putting me nose high by about 1.5". Now I need to lift the rear by 1.5" to get it level again.
Consequences, my lights need to be adjusted driving at night, it looks weird, if I hook up a trailer it really sits nose high. If I wanted it level with stock sized tires, and were to do it over again I'd definitely not have lifted the front at all. It rode "right" and with the stock F250 suspension with the camper installed. I want a little lift though for my taller tires, so lifting the rear is probably exactly where I want it to be, with what I will end up with.
BTW, I'm using all Old Man Emu suspension parts to lift it, an advertised 2" lift.
Edited by SuperDutyFWC, 08 July 2020 - 03:48 PM.