I am trying to remove the balancer bolt on my 351M/400. I have used every tool imaginable, every penetrating oil, hammer and wrench, tried left to unscrew tried right to unscrew and can't get it off. Any suggestions on what I can do next? The motor was left out all winter by a mechanic we had left it with for installation in a truck and I am cleaning it before sending it off to be redone. Thanks for your help.