Another night I decided to work on the high idle issue.
I started by trying out my new smoke machine.
I capped off the intake with a 4" plumbing test cap.
I wedged the throttle disks open.

I removed a brass plug and installed a barbed hose fitting.

Smoke machine attached

I was surprised how tight everything was. The only place I saw smoke was on the W-pipe and eventually on the dipstick.