I mounted my dual Firesticks on the 2nd bolt out. The CB shop that tuned mine recommend that, to get away from RF reflection from the cab. I didn't know any better, so followed his advice. I have one Firestick for VHF 153 MHz and one for CB. Even with the RH side out on the 2nd bolt, I still get banging into the factory antenna in high winds. Also, if you are carrying a slide in camper, the close bolt will bang on the camper overhang, and the 2nd bolt out will too probably, it just gives you a little more room.
Shelby