Currently shooting a Bear Strike at 60# and 28 inch draw. Arrows i'm using now are Easton st excel 400's. Grouping is decent but i've been looking for a heavier better arrow. My question is now, would i benefit much if i upgrade to Easton FMJ's at 330/340 and replace my 100grain with a 125? Not sure how right i am, but i'm kinda giving up on speed with my bow and going for energy. Correct me if i'm wrong in going this way about arrows.

Any and all info is helpful.

I think the arrow you have now would be better for your set up. You can still use the 125 gr tips. IMO the 340 may be too stiff and you may not have as good a flight. In fact, I would be willing to bet that with 125 gr tips you will be getting better flight than with the 100 gr tips.

X2, that's basiclly the same set up I have, I do use the 340's because I shoot 220 gn Muzzy Phantoms.
It's actaully better to be on the light side of spine than too stiff if your on the border.

X3, and it would be so easy to do. 125 gr tips are cheap. Buy some and give em a try. If you're hell bent on getting heavier arrows then look for the same spine (400) in a shaft that weighs more in grains per inch. I would not go up to a 340 spine.