I am in search of a replacement o-ring that mounts under the metering valve on the power steering box in my 69 Charger. It is the small aluminum block held on to the box, by two 1/4" bolts, where the return hose connects. I've been searching all afternoon and all I can find is a complete seal kit. I'm not going to spend $50 for a complete o-ring kit just for one o-ring. Does anyone know where to get this particular o-ring separately or what size it is?