I bolted one together with a Wilson 6.8 barrel mid-length gas, I used all standard components except it has a stag 6.8 bolt and bolt carrier, I put an H in it and it runs fine. It has a standard low profile gas block but I cannot remember which one I used.
Maybe I am over-thinking it. First full build so I am trying to sort it all out in my head before going broke on parts swaps. Maybe you only need the adjustable gas blocks on the 308's.
Then there is this noveske switch block for running a can or altogether negating the gas system.
I wish folks would quit making all this new stuff so I could get on with life... LOL