I'm 18 and drive a 1967 mustang 390 twice a week. I know you're thinking I'm probably just a spoiled brat that has no idea how to work on classics, but I'm very mechanically inclined. My dad and I have always had muscle cars, and I was always there helping him work on them, and learning how to fix them. Recently, I was coming home from school, and I noticed that my car was over revving, and not shifting when it was supposed to. It would get really loud, and then shift, it had never done this before. I also noticed that the oil pressure was spiking, and now whenever I start it up, almost instantaneously goes to high. I at first thought it could possibly be a head gasket, but as of now, I have no clue what is wrong with it, and neither does my father. If anyone has the slightest clue as to what this could be, your input will be greatly appreciated.