GMC 305 v6 Holley 500 swap woes

[AngryPirate]

Originally Posted by Matt's k5

It's needs to be ported vacuum source, also make sure the coil has 12 volts while cranking and with key on, a lot of electrical issues come from bad connections at main firewall plug corrosion, this is what supplies 12v to the ignition switch from the starter,you'll have to run a switched 12v supply to coil If your running pertronix to bypass the factory resistor wire, also I've had a Holley 4412 give me grief ,it would randomly flood out for no reason nothing would help ended up switching out for another one , I believe the factory shiny coating was plugging up something, I've been running my Holley and pertronix no since 2018 everyday no issues your welcome to text me at 80-836-6353, for anything related to the V6

Thanks for the response Matt!

I do have 12v going to the coil.

I called Holley and they said that the port I was using was the timed vacuum port to be used with a vacuum advance. I was using the oval shaped gasket that came with the adapter plate and not the one with the 2 round holes that match the carbs bottom intake holes.
it seems that the gasket closes off 2 small holes in the bottom of the metering block to create a sealed a "vein" between the 2 holes which should create no vacuum unless acceleration is applied.

It helped for sure, but it's still not running correctly.

I'm out of town at the moment but my next thing to check is to see if my timing chain is correct and hasn't skipped a tooth or something. I guess the "put something in cylinder 1 like a pencil and rotate the crank until the #1 piston comes all the way up and before it goes back down" and that should be TDC on the crank pulley marking?

Thanks again Matt and all for the information. It's been helpful.