I removed the factory front sight tower gas block from a DPMS .308 AR barrel and was left with two holes from which the taper pins resided. In order to install a clamp on or set screw type gas block, do these holes need to be dealt with in any way? Do they weaken the barrel if not pinned? Do I need to drive pins flush into these holes before installing a different style block? Or am I stuck with using a taper pin arrangement?