Does anyone have any thoughts on the best way to mount a fireplace mantle beam? I've got a solid cherry beam about 5"x10"x5.5' to mount above my fireplace. I'd like it to be a floating mount with no corbels. Estimated weight maybe 150 lbs.

There is a 2x6 mounted flat to the wall studs with the stone surround. The studs behind it are marked.

I've considered drilling holes in the wall for rebar and then drilling matching holes in the back of the beam to slide on. This seems like it would hold well but I have my doubts about getting it level.

Another thought was a large piece of angle iron and then route a groove in the back of the beam to slide on. I think I would probably have to put at least a screw or two into the angle iron from top or bottom to feel good about this method.

Any other thoughts or ideas? Photo below is of the mounting location. Thanks!