Not to take anything away from site sponsors or anything, but I needed a fix for my leaky cap and could not wait for a billet cap. So I went to Kragen, CSK, and bought a O ring assortment kit. I also bought some dielectric grease. I grabed the next size larger O ring from the kit and lubed it with dielectric grease and after 3 oil changes, it still holds a seal. I will probably change it with a new one next time, so for less than .04, problem solved. I think the key is the grease. I tried it without and did not have the same results..... Sorry if this is a repost....Or a rediscovery..
You wouldn't happen to recall the size of the O ring you used, would you? I have an SAE assortment, and maybe one of those would work. Or I could buy a metric set also.