Ive got a 79 fox with an 89(ish) 5.0 HO in it. The car ran when parked but sat for about 20 years with no spark plugs, which is very not good. Went to rotate the crank to reinstall pushrods and rockers and it moved maybe an eighth of a turn and then stopped, guessing its seized from rust. I already sprayed it down with PB blaster and ill probably keep at it for a few dats before I try to rotate it. Is there even any chance I can free it? And assuming I do, will the rings and bore be intact enough that i dont have to pull the heads or tear the old engine down? This engine was supposed to be just put back together and new fluids and hoses so i could drop it in my 93 for the time and im hopping i dont have to rip it apart.