Well, I'm an old-timer and have been building wooden arrows for about 17 years, so I think I would be qualified to answer your question. I taper my own shafts, from my experience, I say you should shoot the same spine whether parallel or tapered. I shoot both and see very little difference in the flight. In theory, the tapered should clear the riser better, so they may be less critical to exact spine, but there is no problem with a 5 lb spine group with parallels. I think the 5/16 nock looks alittle more tidy on the end of the shaft but as I said, no difference in flight. Usually about $.50 per shaft to taper, so its up to you. I would say try a dozen and make up your own mind.