I use a Martin Phantom at 63 lbs. Gold Tip 5575 XT Hunters and 125 gr 4 or 2 blade Muzzy's for everything.

Your broadhead setup sounds heavy enough, but I would increase your draw weight quite a bit. I would suggest a minimum of 65 lbs and closer to 70 if possible. Bears have a heavy layer of fat, thick fur and heavy bone mass. To get a good blood trail, your arrow is going to need to penetrate and exit low. To do that with an animal like a bear, you're going to need more poundage on your bow. If you can't increase your drawweight enough, I would suggest not hunting with a bow and go for a shotgun with slug. To be an ethical hunter, you need to use an appropriate weapon that will put the animal down quickly. Shooting a 55 lb bow won't give you a high percentage kill shot on a bear.