Leveling a fifth wheel on a truck is problematic with most newer fifth wheels and nearly all late-model 4WD trucks. The Reflections come with the axles already underneath the springs, so "flipping" the axles is not an option - but you could put blocks under the axles. You want to aim for at least 6" of bed rail-to-overhang clearance and no more than an inch or two out of level front-to-back on the trailer. As Mark mentioned, it's not so much your bearings you need to worry about, but the tires, the springs, and the spring hangers (a weak spot). And yes - 4WD trucks tend to sit higher than RWD trucks.
Rob