You don't need to go spend 100-150 bucks on a set of limbs! Your bow is plenty good enough. Your arrows should weigh in at 402 gr. That is too light, A 125 head would put you at 427 gr and 12.1% foc. That would work. I personally would not go under 450 gr. You already use muzzys, Dont change!!
My arrows for elk are 6075 term hunters, 125 3 blade muzzys, with feathers.
487 gr.
11.6% foc
65 lbs @ 28 draw
Elk are TOUGH and big boned. You need a fairly heavy arrow. IMO muzzys are the best and will go through bone
.......good luck