I'm going to be replacing the fuel injectors and have found that there are at least 3 o rings connected to the fuel rail. The first is on the pipe connecting the 2 halves of the fuel rail, near the fuel pressure regulator. The other 2 are on the fuel lines you disconnect at the front of the engine to free the rail to be removed. Can anyone tell me the exact sizes of all these o rings or what kit I should buy that has a large variety of rings to choose from(and really, how to determine the size so I don't use one too small or too big)

The front and rear crossover tubes use different size o-rings. Try a GP Sorenson 8009211 kit.

The o-rings on the feed/return lines are easily available through your local parts store too. GM parts # are 22514722 and 22516256. Borg-Warner 27478 or Niehoff 27478 are cross-references.

HTH

Thank you VERY much for those part numbers. By the looks of it, I'll need to order them off one of the sites. They're not showing up as available at the local stores, just through the mail. Perfect though, so much better than guessing at the correct ones.

I'd try Advanced Auto or NAPA.

You've been very helpful, thanks very much. I'll give those places a shot and then call other stores and a few dealers before I have to order.

I have one last question. I've noticed that the v6 engines have an o-ring on the distributor shaft. Do the v8s have this too? If so, any idea which one I need?

Yes there is a mounting gasket on the distributor. Fel-Pro 70194.

Yeah, that I have already. The new one happen to be blue. Hmmm, I mean... A rubber o-ring on the distributor shaft itself. Like, it'd be inside the engine/intake before I pulled the shaft out. The gasket sits on the intake between the bottom of the distributor and the intake. The o-ring I mean would be on the shaft, if there is one. I don't see mention of one anywhere, but I'd rather be safe than sorry later on.

So essentially what I'm asking is, I know there is at least one gasket for the distributor to seal it to the intake(material/paperish type). Is there a second(rubber o-ring type) on the shaft that goes in the intake/engine?

GM part number for the complete fuel rail o-ring kit is 17111696. This contains all the necessary o-rings for the crossover tubes/regulator.

I would have given him that part number, but he was also concerned about send/return fuel line o-rings that are sold separately, not in the fuel rail kit.