Ok, the conclusion to all this. Got the new metering block from Holley, same result. Probably my fault, but I reminded them, (may not have told them in the first place, thought I did), that I'm dealing with a 540, and they said, Oh, in that case there is nothing we can do for you. This is designed for a 440, and will supply it well, but we can't do or say anything about a larger displacement engine.

Called ProMax, and they said "Yep, that is what our metering blocks are designed for." He also said the six pack metering block is an odd duck, in that it doesn't have an idle restrictor passage in the usual place, which started all this.

So I live with it, or get a Promax block, as Ricky suggested.

All I wanted to do was clean up a stinky idle. I'll live with it for now...