I am trying to temporarily block the gas port on a .906 double pinned gas block (no set screws). I don't have time to find a .906 low profile and mount it in reverse like I normally would. This upper has conventional two piece handguards which I want to keep for now, so gas block needs to go back on in normal direction. I was thinking about mounting a gas tube in the block that was terminanted (pinched close). Has anybody tried this? Any other ideas? I need to get this done tonight.