I've been running halogen 7" sealed beams in my 66 for many years, with no problems. Nice and bright, too. It helps if your wiring is in good condition, and I like to keep the connectors pristine with a little silicone grease in them. Some people like to use a 69 headlight switch to add a little capacity, but I haven't needed to do that. If you really worry about this, there's a ready to use plug-in relay kit for you. Glazier/Nolan calls it G09558.