I bent the axles on my Milan 18CK. It is 4200 lbs. dry, 7K GVWR with 2 3500 lb. axles. I had already flipped the axles for ground clearance and added shocks. I ended up replacing the two bent 3500 lb. 2 3/8" tube axles with 3" tube axles that had the 3500 lb. #84 spindles and brake flanges. They were made to order by AL-KO to exactly match my axle length. Check the AL-KO catalogue, I believe they are in it.
Keeping the 3500 lb. spindles/flanges allowed me to simply transfer the brakes and hubs, and retain the same wheels. The axles I received did not have spring perches, and those had to be welded on. The spring perches can be welded for over or under mounting. I had to get new larger U-bolts to accommodate the larger 3" tube. You may need larger mounting plates too. The shock kit plates I had already installed were good for the 3" tube.
I have had this arrangement for 5 seasons now and have had no more axle problems. I make several trips a year into the Nevada desert on fairly rough dirt roads (the same roads that bent the stock OEM axles!)