[TedRamAirII]

I said this before, and say it again. You need to get your hand on that engine, before its idling for 10 minutes and too hot. FEEL for the noise. I cant believe you have a guy right there with all this Pontiac Experience and has no clue on where this noise is coming from. Get a wooden stick and put it to your ear and start poking around. After 10 minutes, you should at least have a good idea where it originates from, and go from there. Even make a slow motion video, with a timing light on the balancer, and see if its every revolution, or every other. Then home in on exactly where it is in the rotation of the crank. That thing sure shudders, I know that's not right, that should be smooth. Hard to imagine it could run so good on a Dyno, then get installed and turns to crap. Its going to be so simple, and embarrassing when we all find out what it is. I cant blame you for patience wearing thin, I would certainly be tearing my hair out by now. Did you crank it up with all belts off? Harmonic Balancer torqued down? front pulley bolts all tight? Fuel pump quiet? Feel the dipstick, all good there? Dist cap? Get your hand on things and feel for the noise.