Mine was always hitting the garage door so I cut down to the same level of the roof.
No problems with the reception.

 

Go ghetto and cut it off. Cut 5.75 inches of mine off today with my side cutter. Pulled the ball off and jb welded it back on and painted the ball again with some testors model paint and walla. No more hitting the garage door and it is still a few inches taller than the cab. Reception is great.

 

that's what I did and it worked great.