Those fabcrap arms won't support 37's. I fix and clean up the failures of fabtech trash all day in the shop. Unfortunately there are no real suspension systems on the market for these trucks. The best thing to do if you want to run 37's without blowing apart every component of your suspension, is have upper and lower arms built, and get a spindle machined that will support a Dana 44 spindle, running uniballs. The tradeoff here is that it will make the front end significantly wider which isn't ideal for a DD.