55o gr would work well for most 55 lb bows. Sasquatch will at 55 lb should shoot good with 600 to 650 gr. You are pretty heavy. I think your variance in weight would cause more problem with accuracy than the actual weight of the arrow though. You can learn trajectory if you shoot a lot but its hard to get good groups with varying weights of arrows.
I would suspect head weight variations are the problem . due to sharpening perhaps.

God bless, Steve

I add 3/16" poly rope to all my arrows.. Quiet bow and a hard hitting arrow works every time.

My arrows are around 700 grains on 55#ish bows. Learn the trajectory and it won't matter the distance. This doe was a little over 30 yards and I doubled lunged her, but she ran out to a bit over 50 yards and quartered hard toward me. If I gave her 30 seconds she would have dropped but I don't like to take chances. The follow up shot entered just I front of her near leg, along the sternum and exited through the offside leg before sticking in the snow. I was very impressed with penetration and I dont feel I'm giving up accuracy.

I think you'll be fine. 55@31 is substantially faster than a 55@28. My go to bow is a 52@30.5 Hill and my arrows weigh 625. While my gpp (12) is a touch lower, I can guarantee you that your bow will shoot your arrows faster.

I'd spend some effort getting a matched set and then sticking with it. Get your eye trained to that arrow flight and you'll be good to go.

That is a bit on the heavy side for my taste Jim. But i like my arrow trajectory pretty flat.

That bow will shoot those heavy shafts just fine, but i would recommend 550-600 grains for elk and get a flatter shooting arrow and still have plenty of power to it. This also helps a lot if you miss judge your yardage.

The bow really slings them. My last ( and only) was killed with a 625 gr arrow out of a slightly lower poundage bow.
When I got this bow I changed from 3 under to split and I never really got the release as good as I wanted it. I went back to 3 under and my release is a lot better. I shot at 30 yds last night and like some of the guys here have said once you get the trajectory down everything is good. I like the weight to help dampen the sound also. Big do they thump the target. You made me a heck of a bow here Kirk. Thanks Guys