Only thing I have ever struggled to remove has been a couple of crank pulley bolts which have taken a 6ft bar and a lot of force to undo!
I wouldn't recommend using an impact gun with a non impact socket as previously said they have a tendency of either splitting or shattering, neither of which you really want to happen!
I wouldn't recommend using an impact gun with a non impact socket as previously said they have a tendency of either splitting or shattering, neither of which you really want to happen!