Too many good suggestions to reply to each poster, but I sure appreciate all of your inputs. Right now the trailer is in storage, so information will provide me a good starting point this spring. I’ve had the trailer since new in 2005, the first time I had a stud failure was 2008 on the right rear. Since then I usually break one or two on the Rt rear when I travel from Montana to Texas. This last trip the Lt rear broke one.
Some additional info that I should have supplied in my OP is; I changed the standard lug nuts to the chrome acorn type. The trailer is about two inches higher in the front. The axles are 5200 lb, and the scale weight on both is 9250, I didn’t weight each axle separately, but I should have.