well i would say a good 5-7mm is stuck in the bulkhead, and it starts about 2mm from the top so i cant grab it with some pliers. I didnt use thread lock on it so if i could stick something on it it shouldnt take to much to get out. And what makes it worse is i've only ran my truck about 5 times with these on. i hope the warrentee covers it that would be great.