True 12 volt source for Choke

Got a 67 coronet with a 440 and a Holley 870 street avenger carb. Car has a hard time starting, need to rev and hold it at 1200 rpm to warm up a little so it will idle on its own and has a ruff start till it’s been warmed up for a min or so.

I’m thinking my elec. choke is not working properly and causing there ruff start issues. Holley recommends a true 12 volt source, it’s been getting about 9.7 volts from the blue wire w/tracer from under the dash which (I think) goes to the alternator regulator.

Does the Holley elec choke require a true 12 volt source or should 9.7 volts work? I’ve measured the voltage at the dark blue wire at the alternator regulator which is about 9.7volts.

Any ideas if I need a true 12 volts for the choke to operate correctly?

The driver side of the white thing on the firewall that reduces voltage to the coil has true 12 all the time under cranking and run.

From your info, it actually sounds like your choke may not be closing versus being slow to open or not opening fully. Check choke when engine fully cold and not running, give throttle a quick, short pump and choke should close fully. BTW, I always run a fused hot wire directly from ignition switch ( key on hot circuit only) to electric choke thermostat, to insure full opening voltage.

Blue wire on ballast or regulator will feed 12 volts.

The blue wire running to coil spliced into the brown wire to ballast only gets 12 volts when cranking. Other wise will be on 4.5-9 volts rate depening on temperature and RPMs