I replaced the O ring with a new ring, and it still leaks. Is there another O ring I can use to fix it? Any suggestions?

 

What does it leak ?
Do you mean that moisture can get in the distributor cap ?
You could always try high temp liquid gasket (the same stuff used on the valve cover gasket to seal the corners).

 

are your sure the oil is coming from there?

 

Sure it's not your head gasket?

 

well it appears to be coming from there. it looks like its coming from that area behind the distrib cap, and leaking down to the front left of the head gasket. Its really hard to tell if the head gasket may be leaking as well, but I have already had the bottom end decked, and the bottom of the head smoothed out. They found .003 inch variance in the left side of the head, that they were supposedly able to correct, but cant go much more because im running CTR pistons and clearance will become an issue.

 

It could be the valve cover gasket leaking from one of the corners in that area. You could remove the valve cover and inspect the gasket to see if its not damaged.

I doubt it would be the head gasket leaking oil