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**'68OrangeSunshine** · 08-13-2018, 04:58 PM

On the Jegs website, when you hit''description'' one of the options is a Holley film clip on Power Valves, which details a test for checking out the PV's status.
Also, they have put in a new checkball in the carb body that supposedly protects the PV from minor backfires. ''New'' since 1992. I bought my Holley 390 in '78, so I was plagued by bad power valves.
If your original PV checks out OK, it's good insurance to keep a spare in the glovebox -- next to a spare HEI module.
As Caddylackn says you need a full 12 vdc feed to the HEI coil. The old yellow 20 wire that went to the points coil will drop to 7 - 9 volts as it warms up. This keeps point from burning up. Not necessary for HEI.

08-13-2018, 04:58 PM	#14
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,098	Re: 69 C10 l6 lack of power with 4bbl, offy intake, exh manifolds On the Jegs website, when you hit''description'' one of the options is a Holley film clip on Power Valves, which details a test for checking out the PV's status. Also, they have put in a new checkball in the carb body that supposedly protects the PV from minor backfires. ''New'' since 1992. I bought my Holley 390 in '78, so I was plagued by bad power valves. If your original PV checks out OK, it's good insurance to keep a spare in the glovebox -- next to a spare HEI module. As Caddylackn says you need a full 12 vdc feed to the HEI coil. The old yellow 20 wire that went to the points coil will drop to 7 - 9 volts as it warms up. This keeps point from burning up. Not necessary for HEI. Attached Images __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.