Idle vacuum at TB on the IC side?
 

Anybody ever put there hand over the throttle body at idle? How strong was the vacuum? At 1000rpm idle the vacuum there is enough to suck my hand in at about 1" from the outer edge, and it's very hard to remove. I've set the stop so the crank isn't bottom out on it and there was no change in the vacuum strength. I've been trying to find a vacuum leak, and arrived at the TB after sorting every vacuum line in the engine bay.