Im in need of some assistance as i dont have a lot of time to play around. I shoot a 64' Treadway Longbow 52 lbs @ 28' and draw 27.5 at around 48 lbs. I have a dozen uncut 3555 gold tip trads. If I cut these to 30' with the standard insert and a 125 gr point, the will only weigh aroun 410 grs. I want around 10 GPP. So Ideally 480-500 grains total arrow weight. If I put a 100 gr brass insert in with the 125 gr point, what length would you folks reccomend the arrow to be for correct spine. Thanks a lot.