I have found my Hill bows tend to like arrows spined at, or about, the stated draw weight of the bow. For example, my 55# Cheetah likes arrows at 55 - 60# spine. This makes sense, though, because my draw length is about 27.5 inches with 29" shaft. I shoot 125 grain Zwickies.
My 65# Wesleys are a little different. Both are 65# draw weight. One likes 65 - 70# spine, but the other likes 70-75# spine. I shoot 145 grain heads (135 grain when using Magnus). Both shoot okay with either arrow, but, each bow has a very slight difference in what it prefers.
My 50# Big Five likes 50-55# spine with 125 grain points. Keep playing around, and you will find what your bow likes best. Then go shoot Bullwinkle!