Ive got 2 hammocks. One is 10 ft. the other is 11. I cemented 2 head posts in at 7 feet center to center. I want to hang both at the same time. Posts are 6.5 in. round. They are 2 ft. in the ground with 6 feet out. Now Im nervous about cementing the others in. My idea is 13 ft. Is this gonna work for me? Should the feet be wider spaced than the head? Should I go 14 ft? I plan to cover with 2 tadpole tarps. Thanks for any help or experience you may have to offer.