Ive got a REALLY loud tapping right under the plenum by the distributer. It starts tapping randomly too. Not everytime I start it up, but when it does start it varies with the engine speed. I know it sounds like a loud injector but I've never heard one before and this is really loud to me. What do you think? Also Ive been meaning to tear apart the top end for a while, but I know I need all new gaskets (140k). Is there a set I can buy?

 

For gaskets, just go to autozone and tell them what you are doing...they can hook you up with a couple different sets depending on how far you want to go into your top end.

for the tapping sound, you can use a long screwdriver. Just put the pointed part on whatever you think is tapping, and the other end pressed against your ear. Wherever it is loudest is where the tapping is coming from.
I've also heard of this trick being done with and old heater hose with something metal and pointy stuck in the end of it, and I guess there is a stethoscope of sorts that you can buy for the same purpose.