Rocker arm o ring.. I don't think this may be 25 specific but It is to simese motors. I don't think the guys in 40 tech will be as helpful since this a 64 is a real early 40 Anyway. WHere the rocker arm comes together at at the banjo for the oil feed there is a banjo, a fitting and a spring for the fitting. Is there supposed to be 2 O rings there too? I'm new to the F135 Thanks Nerd if you feel this needs to be in 40 that's fine..