Air lifts still needed?

I was towing a Fleetwood popup with a 1997 Nissan Pathfinder. I had air lifts installed in my springs. I will now be towing a 2000 2720sl with a 2004 Nissan Pathfinder. Max tongue weight on the 1997 was 250. Max tongue weight on the 2004 is 500. I do not want to use a weight distribution hitch. Should I have the air lifts switched over to the new vehicle?