Pinion nut won't loosen.

Just about done with winter maintenance and I'm just at the point of putting the gear stack back in the gear box of my FE but before I do that I want to remove the pinion nut and check torque, which I've not done since I've purchased the car last year. I would only check it after each weekend and it would always be on nice and tight. Normal torque rating for this nut is usually 180 ft/lbs with some red locktite, however, I've got an insane amount of torque trying to back this nut off and am at the point where I'm permanently bending the breaker bar by using a cheater bar. I've put some heat to the nut and then quickly applied torque using the special removal tool and no luck at all. How much force can I put against this thing (Elite/Staffs gear box TX200) before I start making my wallet a lot lighter? The tool has me applying torque to the pinion shaft while it holds the pinion nut in place. Pinion nut is left hand thread but since I'm applying the force to the shaft I'm turning counter-clockwise. Thanks for any and all advice!

Pinion nut won't loosen.