Google "Raptor Lean" it is a well known thing.
You can try swapping leafs side to side to see if its an actual leaf sag issue, more than likely it has done this for a while and you just noticed after working on the suspension and being more aware now.
Raptor springs are soft... The fuel tank hold 250lbs of fuel, there is always a driver on that side, so over time the truck will lean.
Did you set the front coil-over pre-load the same on the Fox 3.0's? Sometimes a couple trurns on the Drivers front will help push some weight to the opposite side, but its marginal.
BTW, I am on Deaver +3 and after many off-road trips mine is doing Raptor Lean too.