42 gm hei distributor parts diagram
The GM HEI distributor uses a hall effect for the triggering and sensing the No.1 cylinder location and the rpm of the engine. It uses an ignition module within the distributor to regulate the timing curve as well. It will automatically advance the timing on acceleration a specific amount and retard the spark when decelerating and starting. An HEI is a reliable source of good spark, however when it dies, it dies in a hurry, not slowly like points-based ignition. I now (after a $65 tow charge in the middle of the night) keep a spare module (less that $20), a 1/4" nut driver and a flat blade screwdriver under the seat. Events and seminars hosted and/or organised by the IDM are indexed on the respective IDM calendars. Kindly note certain events may require an R.S.V.P or registration. Gm hei distributor parts diagram