FYI,
I just had to remove the balancer bolt on a motor that had already been removed from the truck. My impact wouldn't do it. I removed the valve cover, placed a large screwdriver in the timing gear with a piece of wood wedged under it to protect the top of the head, placed a 6 point 19mm socket on the bolt, used a 3' breaker bar with a 2' cheater bar and viola! Well not quite viola....it took a few tries to get it just right but it came out.
Just thought I would update in case some one else runs into the same thing.