odonnell

I have a nice Ingersoll-Rand 1/2" drive impact with a 5 CFM supply and it didn't budge them. Lots of rust. The break-free torque is often significantly higher than the spec torque. But then again that was for an early steel-arm car where the torque is a lot more, in general I agree an impact is the go-to.

gruhsy

Funny you mention 650 ft/lbs. I just bought a brand new Canadian Tire Maximum impact gun that rates at 650 ft/lbs. It would not even budge it. Luckily my dad is sending me his 1 inch drive gun that we use to take large hardware such as track pad bolts and C-frame and blade bolts of the Cat D8 bulldozers back home.