>>>*K...But you will reach my son Tod who will have no idea, might be best to just email me. Tod runs the machine shop, he doesn't know about emissions I don't think.

About the only thing I can think of that would cause both high CO and HC is if the added airflow causes the computer to try and compensate by adding fuel, this because added airflow should result in a mildly leaner condition?

In the old days we would just pull a couple of degrees of timing out and go pass the tests.

One trick to try is to loosen the valve lash to stock specs, this shortens the duration and reduces lift slightly while advancing the valve timing. It will run a bit noisier but won't hurt anything, and it might just be enough to keep it from confusing the computer which is almost what has to be happening....*EB