I had a 72 GMc Jimmy I had bought at one time that had a plw set up on it since it was brand new. Bolts huge and rusted on real good. I wanted it off in a hurry and the location of the bolts I just couldnt break them free, and didnt have access to a torch at that time. Break out the reciprocating saw. The steel where I was cutting had to be 1/2" to 3/4" thick and 4" long. A Fine 6" metal blade, and a frequent squirts of WD 40 as someone else mentioned, and I was through it in about 2 minutes.