HELP!!!!! Does anyone know who makes a 14mm to glow plug adapter with a square cut (flat) "gasket type" seat where it seals on cyl. head???? All the ones I've seen have taper type seats. I have 1 eng. that someone has used a tapered adapter on a flat gasket type cyl. head and it leaks badly around threads. Also I can't find a countersink type tool to cut a taper in cyl. to fit adapter, without going into a big, big production thing!!!!!