I have the FX with the minimax 28 " and 66-67 lbs. The 5575s were slightly underspined the 7595' s fly great. I think that if you weigh those arrows you' ll find that you' re real close to 5 grains /lb, that would be one concern. The second is that you' ll be slighty underspined with the 3355' s. Maybe with the smaller prolife of the 75 grain head you can get away with it. I' d probably keep the 3355' s for 3-d and think about goiong with some 5575' s for hunting. I wouldn' t go to a heavier head on the 3355' s. Your FOC should be around 10% which should be fine and if you go heavier on the point the spine will surely be weak.

Let us know how the broadheads tune for you on the 3355' s.

I too would go with a helical or offset at least.