Alight guys a little up date and some interesting information. So I got to go to a local traditional archery shop today " bayou traditional archery" owned by Mike Harbison in search for a carbon arrow set up for by 66# recurve. Now in my research I have come to believe that a 340 spine maybe even a 300 spine carbon is what I would need to get a good flight out of my bow, Harbison is a gold tip dealer so this is what we did our testing with. We go set up at 20 yards and he gets up above me standing behind me so he can observe my arrow flight as I shoot. First I knock a 5575 29 1/2" long 150 up front, shot it a few times but it had a noticeable "side whip" in flight. Next we shot a 5575 29" long with 125 up front with a weight tube, shot s few times with still a little "side whip" in flight not as bad. So we put a broad head on it and shot a few more times trying to get goog flight. Not 100% satisfied mike went back into the shop and came out with a 3355 cut 29" with 125 up front, and he said let's just try this and see how it flies. I knocked it, he stood above me and I let her fly, and we both said it at the same time holy sh"& that thing flew like a laser beam dart. Shot it a few more times and every time we were amazed, or atleast I was. So we looked at our options and decided a 3355 with a weight tube cut 29 1/4" long with 125 up front gave me a total weight of around 580 I think, which is a little lighter than I would like but they fly like darts and hit like a sledge hammer, I was sinking them about 5" from the fletching into s styrofoam block, this is with a broad head now. So just wanted to let y'all know about my experience and see what y'all thought about it. But one things for sure Mike was a huge help and runs a nice shop, he builds custom strings and fletched and crest some beautiful arrows.