Ians idea is to block a small part of the hole and involves a temporary block that is easy to remove. I will follow your recommendation to exhaust tuning efforts via idle air correction jets sizing first.

Yes, I was referring to the PMO bulletin you posted.

Since I first posted this thread we have: increased the flow and volume of the air filter, installed a vacuum signal and added timing for light throttle at low rpm’s, and added the MSD for increased spark efficiency.

All these changes have improved AFR’s at light throttle while at 3300 rpms at 72 mph I’m seeing 12.6-12.8. But at 3000 and 60 mph I’m only getting 12.2 - 12.4.

So hopefully by changing the air correctors it will continue to get better.

It would be ideal to have a throttle position sensor so you could determine relationship of edge of throttle valve at various cruising speeds.

I'm interested in your progress, keep the faith and good luck.