What gas blocks work best for these? I'm thinking up a 14.5" to 16" lightweight middy (Centurion or Noveske N4 barrel) and would like the 11" or 13" rail to cover the gas block. My gut reaction is to get the barrel with a normal FSB and shave it down for weight and cost savings, but if there's a better option that allows easier attachment of rail sections then I'm all ears.
-B

