Roof should be here Tuesday. I'm 5'11" so it might be a little more snug for you. The rack doesn't hang below the rear cross bar so if your head is below that you should be fine. I saw another gun mount on thus forum that mounted towards the rear of the cab which might give you more head room. It was a single gun mount. The moose roof appears to fit very snug along the roll cage so I would venture to say it won't work. You can see in my first and second picture how the forks of the mount stick up above the roll bar.
2015 Honda Pioneer 500
2013 Honda Rancher 420 2wd
2006 Honda Rancher 350 2wd (traded)