I have a yankee hill midlength light weight free float tube on mine with paladins 3 pos gas block. My tube just barely
fits over it after rounding the corners on the gas block and the rotating selector and shortening the lever in the selector. with the carbine length tube I wouldn't have had to open up the lightening holes on my tube but with the mid length I did and am very happy I went this route.
It looks factory and gives me lots of room on the tube for mounting accessories.
Hope this helps