I have done about 20 sets off stacks on various trucks and have had to cut the same piece. I have not had any problems in doing so nor have I had anybody complain about any issues. There is alot of support up there between that cross piece and the fact that the bed head board are connected there. I would say that the bed head board will provide plenty of strength as long as you don't plan on loading the bed to the max. Good luck would love to see some pics when done.