Need help!!!! My rebuild kit from fel-pro came complete with 24 new valve guide seals but they are nearly identical and are not marked! You can see in the pic the subtle differences. The one on the left has a little raised lip in the middle of it. The one on the right has 3 even smaller ridges non the inside. The hole diameter is identical and so is everything else. Which one is which?!?!?#@$%!