I've got twin 1990, 454 Crusaders (FWC). I've always used an old hand pump to change the oil. I went to the marine store today to check out what they had. They have the hand pump type, one that attaches to a drill and one that has an electric pump that runs on a 12 volt battery. Anyone have an opinion on which one I should buy? Do all of them simply slide over the top of the dip stick tube?