Little Advice To an apparent idiot.

When you say shooting out the carb do you mean out the vent tube at the top? Sounds like it is just dumping fuel into it...try tapping it on the side, or take if off and shake it around a little. Float maybe hung up...how long has the carb been sitting or how old is it?

It does depend on where the fuel is dumping from, but as already mentioned it's likely either a stuck float in the carburetor, allowing the fuel to overfill the bowl, or a fuel pump that is pushing too much pressure (usually only possible if you have an electric pump, but Mike mentioned his issue with a mechanical pump) and overriding the float spring so it can't close, and overfilling the bowl.

You could also have two different issues with the two carbs. The Edlebrock could have a stuck float, while the Holley could of had a blown power valve.

Short of knowing where the fuel is exiting the carb, I like "Rides" idea of pulling the carb giving is a good shake as maybe the float is stuck (this could be a quick attempt at "fixing" it. The cfm of the carb is probably a bit big, but the vacuum secondary style gives you a lot of leeway, so unless you don't mind spending the money on a new carb (they ain't cheap) I think it would do fine. My opinion anyway.

be careful shaking a carb or turning it upsidedown, the float tang could bend slightly causing incorrect fuel height. tapping the side of the carb with a screwdriver handle usualy does a stuck float.

Also, untreated Ethanol gas sitting in carb bowls corrodes the inside of the carb and small chunks of crud flake off.

I run a combination that was recommended to me by a marine engine guy.

Marine Sta-Bill
Star-tron Staybrite. I may gotten it reversed, Staybrite Startron. (I can check for sure tomorrow)

Use the Startron as directed, and use double the dose of Marine Sta-Bil. It has to be the blue/green colored Sta-Bil, not the red. This combo will last up to a year.

SOP for our cars, mine is always out of fuel after sitting a couple of weeks.

Well, that's very good info and does not change what I do. Mercury is just wanting you to buy their additives. Non of the myths are anything but common sense. I would hope no one here would ever believe that additives can reclaim bad fuel, fix all, or anything else in that vane.

Well the Holley carbs power valve was not blown and the edelbrock carb runs a little better but is still missing and backfiring. Im believing the issue is more internal. The car isn't running on all cylinders so who knows. Maybe a smaller carb before pulling the motor?

I'm with Bro... I don't think a carb change is where I'd be looking at the moment. So has the car been running fine, then the issues started? Or are you just now trying to get it running? Or was it sitting for an extended period, and now it's not running right?

However, I just went back and reread your initial post, and one of the "highlight" symptoms is that "gas shoots out of the carb". Are you still having that issue? Nothing that I know of internal to the engine will cause that, so you would still need to focus on your fuel system.