Just got some 2.5 degree Rancho shims for my 89 Blazer 3/4 ton conversion with a 4" lift (3" Tuff Country springs, 2" Hill shackles). I was a bit surprised to see they were made out of aluminum. Feels a bit strange to be torquing down some soft metal between spring steel and the heavy front end housing. Anyone ever had any problems with these cracking or coming out? Also, anyone know if steel ones are available?