Not sure I would suggest the self adjusting brakes. That may lull into forgetting to remove the drums to check the magnets and you will loose the brakes and destroy the drum. Adjusting the brakes is not worth that.
If you change the rating make sure they will fit the current drums. Brake capacity is a function of diameter and width of the shoe.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles