Do spark plug tube leak oil?

they have the ability to leak really bad. factory mopar seals suck, they are asymmetrical and poorly made. fel-pro makes a set that are very high quality, checker even stocks them. if the tubes aren't out of whack the fel-pro seals seal right away without any other adhesive or sealant. also a big issue for leaking is the wrong spark plugs. if where the plug seats against the inside of the tube has a larger diameter than the flat spot where they seat, it will bend the tube, pull on the outside lip where the square "o" ring is and cause leakage. when i bought my slant, the tubes leaked something horrible. i bought new tubes, the fel pro seals and the correct plugs and havent had a problem since.