I bought a complete u-bolt/stud kit from one of the big name companies (Superlift, Skyjacker, or ???). The studs broke and were a PITA to drill out. Yes, they were the type with the coarse threads on one side and fine thread on the other.
Called Stephen Watson at ORD and he said to just use bolts. That was 4-5 years agon and I've never had a problem since. The biggest thing is to make sure they are always tight.