I am going to take it back apart this afternoon and see if I can figure out what is going on with it. This is my first time doing the gaskets on a LN3 (have done many Series II intakes before though), and this car has actually had the intake gaskets done before by someone using the same felpro kit I used, so I am unsure if they simply left out the O-ring to the L pipe going into the TB or if it did not have one originally. Hopefully my investigating this afternoon will turn up some results. I will also see if I can get some decent pictures of the pipes from mine when I have them out.
padgett I don't suppose you happen to still have or know where to get one of the what appears to be re designed L coolant pipe that uses an O-ring on both ends? My car developed the issue just the other day where a leak formed where the L pipe goes into the throttle body. Taking it apart revealed that while my car's L pipe has an O-ring on the side going into the manifold, it does not have one on the end going into the throttle body. I tried putting it back together with some RTV but it leaked even worse than before. The part number you originally listed for the pipe seems to be no longer in production by GM.