I have always prefered the 90* setting when doing 4 fletch, I actually just did 14 of them up this evening for a friend, and I burned my Motor City Machete banana shape on them. It really all comes down to your personal preference. As long as the feathers are not secondaries, they will be fine. I have found, and regret using in the past, secondary feathers due to the masive amount of noise they make. I think it is because of them being so soft that causes them to sound like flu flu's in flight. Just about any fletch out of primary feather is going to suit you well, and for the most part be quiet enough to slip thru a set of lungs before the deer will hear it.