"Universal replacement' O-Rings are probably not a good idea. Most of the "universal" rings are nitrile rubber (Buna-N) and the fuel system requires Viton. Nitrile will dissolve slowly and create serious/dangerous leaks of fuel under pressure. They are the equivalent of a time bomb.
For the fuel feed and return lines I think you need AC/Delco 217-452. They are about a dollar apiece at many stores like NAPA, CarQuest, Advance, O'Reiley, AutoZone, and other stores, or through the dealership parts department for a few dollars more. The ring I mentioned has a 7.35mm I.D. with a 1.66mm cross section (thickness).