Can you get a swing at the head of the bolt.Some times a shock will get things loose.I work on large heavey Army equipment.and they don't bring the easy ones to us.We call it heavey junk.Once when we were doing a D7G project ,when doing the track frames .We would have the frames removed and upside down on the floor ,rock guards off and tring to get the roller bolts to give 1"x 14 . the bolts were 1- 1/2" whench 10" of pipe and moving the whole frame across the floor.New Guy breaks out an air hammer (like the muffeler shop uses) but with a blunt head. He hammered around the head and down the side along the bolt path and unscrewed it by hand. No
oil ,no wrenches, no torches. honest. I'm always open for new ideas.