I was wondering what the thread size is at the firewall? I'm trying to tap into it for a fuel pressure gauge and trying to avoid cutting my line. I read that it's 14mmx1.5 and also that a -6 AN fit as well. My fuel rail has a port on it but it's not accessible for the sender. I may pull the rail and drill/tap a new port where I have room for my sender. Best options? Thanks.