Dizzy vacum logic.

[Kenall]

can i get an explanation why GM uses ported vac and ford/AMC use manifold?

and which is better?

[joe]

Ken, AMC uses ported also after the eng is warm. The dizzy gets manifold vac from the CTO to help smooth the warm up. When it gets to 165 deg or so the CTO switches the dizzy vac over to ported. If you're not running CTO's hook the dizzy directly to ported.

[Kenall]

thanks