Thanks for all the help regarding penetrating oils. I've tried PB Blaster and Liquid Wrench on very rusted-on bolts on cast iron headers. No luck. I'm not into torches. Would muriatic acid cut through the rust without damaging threads, etc.? Some of you have suggested Kano products. They also make engine degreaser. Has anyone tried it? Is it any good, or is there some other engine cleaner/degreaser that's better than Gunk? Can Kano products be bought locally, or does it have to be ordered from the mfr.? Thanks again, George Clineman [Non-text portions of this message have been removed]