The oil return plugs on the side of the block....anyone know what thread pitch they are? Metric pipe thread or o-ring type seal? Tried getting mine out and think I'm gonna have to put some heat on it...to get it loose.
you have to use an Allen socket + breaker-bar + smack the breaker-bar with a 2-lb hammer with quite a bit of force... they will break free quite well like that.
at 12:18 in this video, i break free one of the small allen plugs in the intake manifold,.. same principle, only the one in the video is on a smaller scale...
https://youtu.be/lUeYsQY0ykM
All the plugs in the ISX with an Allen head are metric oring seal with a 1.5 pitch.