The upper overloads in my 3500 SRW are a joke, they don't come into contact unless the rear axle is at max OEM tire capacity. I have verified this several times on my truck, and I presume this is why dodge remove them on 4th gen 3500 SRW trucks.
With a 1" level I take more air than a stock truck to maintain a level stance, but even then I don't even need 50 psi for 6,400lbs on the rear axle. I know GM suspensions are softer, but not that much.
I still don't think it adds up. Any 2500 that cannot maintain level with airbags is over the tire capacity unless the tires have been upgraded.
My dads 2500 takes 80-90 psi with a 2" level and 8K on the rear axle to be level.
If the OP feels he needs additional spring help over airbags on a 2500 there is something he isn't telling us.
