Ultimately it does not matter what the suspension is capable of... what will matter with the DOT in (you pick the state) is what the door tag says, That is why you see fewer and fewer (pick up based) ramp trucks. Here in the land of Taxes its approx $150 for the first 1-1000 Lbs of over weight,and goes up from there. Not including the impound, towing and all the other assessments they make once they find the first "cause" The second axle will need to have brakes equal to the first axle. BTW these are not NYS DOT regs but FED regs. If you dont plan on leaving you local area you may be fine but once you get out into the bustling metropolis its game on.
I used to have a Ramp truck (late '80s) 10000lbs door tag but 13000lbs going down the road loaded. Nice well maintained truck and could carry a Bulldozer (on more than on occasion) but stopping was another issue.
Those days are behind us...