Answering my own question and sharing some info:
Impco product updates:
http://www.impco.ws/product-updates.asp
Idle adjustment:
http://www.impco.ws/pdf/TSB-167.pdf
Impco ECU interface
http://www.impco.ws/spectrum-test-tools.asp
The taper plug on my carb is impossible to get to as it is right against the hydraulic valve block.
I don't think the Idle adjustment screw tis the proper approach to my problem because the high idle started instantly.
Yesterday I cleaned the crank sensor.
I am waiting for a Ecu interface cable. ($100) My Service shop some how does not have one.
I'm supposed to get a service manual today.
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