How to correct uneven "Bump Clearance" ?

I have a 5th wheel that is slightly overloaded. After about 10,000 miles I began to notice the springs had flattened out and it began to lean on the drivers side (2 Slideouts are located). Because the axles had been flipped right after we bought it, there was no rubbing. However on a trip after the 10,000 mile mark a spring on the passenger side broke. I replaced all four springs with new 8000lb units (Originals were 6000lb). It's much better since the replacement.