PB Blaster is the best stuff for spraying on rusted a bolts. What I do is spray the PB all over the bolt let it sink in some. Than I use a MAPP Gas torch (with propane you will be sitting there all day waiting for it to heat up) and heat the bolt up sometimes until it is red hot. Than spray it again with PB which will cause it to cool very fast and hopefully sort of loosen. Than use your socket wrench on it. If not get one of these...