Jason you might try www.trueflightfeathers.com/ they
were very helpful when I went back to feathers,am
using five inch feathers no clearence problems on the
clearence and my helical is pretty severe! I called them
and they said that the arrow does not start to spin for
about 12 feet and there are no feather tracks on me
rest area. After using feathers again I will not go back
to the vanes because of the improvements in arrow
flight,water proofing is easy and like the way they
react passing through bale,etc. Good luck!!!