spill control valve

New short block, and head with the following changes: EGR blocked off, top mount intercooler. The old engine had a cracked #4 cylinder wall. Everything was tripled checked and probably looked over the timing marks on all the timing gears about ten times over. Timing belt marks all good. So...

Anyone know where to get just the O-ring for the spill control valve? If not I can just get the whole seal kit! I'm not having any fuel delivery issues indicative of a bad one, it's just noticeably leaking from the top of the rubber grommet.