Help me Tom Cruise.. Fuel or Spark Issue??

[CopperLB81]

81 regular cab custom deluxe 305 V8 350c transmission. Has the Rochester m2me carb 2 barrel. By the way I'm not a carburetor guy so I've never been able to get the carburetor where it doesn't burn the crap out of fuel run rich and smell extremely strong.
The truck was running poorly one day on my way home from work it wanted to stall out at idle and while sitting at traffic lights in gear.
So I first dug in to the basics I put a fresh set of AC Delco plugs. I had a new set of accel super yellow spark plug wires. The truck already had a accel super coil cap combo. I removed that installed a fast brand cap rotor and put just a basic over the counter O'Reilly's coil on it. The truck still wouldn't even crank it will turn over but would not start. Then I thought it was fuel related the truck had always ran rich and never could get it dialed in. So I installed a new fuel pump precision brand from O'Reilly's. The truck would then start up but it was running terribly would not stay running and it sounds like it has a dead hole like a single cylinder misfire. I have double checked the firing order multiple times from the Haynes manual I have also checked the fuel I know there's no contaminants in it I put a brand new fuel filter on it when I installed the pump.
I know I should have already checked but I have not done a compression test on the engine I'm hoping it doesn't have to go that far simply because the truck was running perfectly all the sudden it started running like crap in the next morning it would not start at all only turn over.

So please could someone help me understand what's going on with my daily driver I would greatly appreciate any advice that someone's willing to get me thank you.

 

[fast 99]

Really should have come here before shot gunning the problem. Replacing all those parts it is possible to screw up, making diagnosis harder. Check compression, are the plugs black? Being that rich will dilute oil with gas. Obviously need to get that carb fixed but only after diagnosing engine condition.

Not that it may cause a no start but do the advances work?

Check spark, fuel pressure and volume.

 

[CopperLB81]

The plugs were definitely black. And old. The guy at the O'Reilly's that sold me the fuel pump said that he put the same fuel pump brand on his big block and it got too much fuel and he had to put a fuel pressure regulator on it turn the pressure down.
So I'm guessing more than likely since I have a small block 305 with the two barrel carb it's probably getting way too much fuel now with the new fuel pump

 

[Sad Sack]

Just as an FYI: Carb pressure should be 4-7 pounds. Put a cheap in-line gauge in and measure if you think you're getting too much pressure. Always have a vacuum gauge handy, they can help immensely with a running truck and issues. Also check carb bolts / screws and test choke pull off. Rochester choke pull-offs are often bad along with vacuum hoses.

 

[Grit dog]

The plugs were definitely black. And old. The guy at the O'Reilly's that sold me the fuel pump said that he put the same fuel pump brand on his big block and it got too much fuel and he had to put a fuel pressure regulator on it turn the pressure down.
So I'm guessing more than likely since I have a small block 305 with the two barrel carb it's probably getting way too much fuel now with the new fuel pump

Doubt it. Never seen a mechanical pump push too much pressure.
But back to diagnosis.
You have to figure out whether it’s fuel (too much or none) or spark…or compression.
No time to write a book atm but you’ll get plenty of suggestions here shortly.

 

[Grit dog]

Honestly sounds like it could be a vacuum leak.

 

[Camar068]

Just as an FYI: Carb pressure should be 4-7 pounds. Put a cheap in-line gauge in and measure if you think you're getting too much pressure. Always have a vacuum gauge handy, they can help immensely with a running truck and issues. Also check carb bolts / screws and test choke pull off. Rochester choke pull-offs are often bad along with vacuum hoses.

before I went LS, I came across a 1.5" vacuum gauge on an old peice of medical equipment hitting the dumpster. I bent some cheap metal and mounted it next to the carb. Made myself a mental note of what normal was. This helped out a few times before going LS. Haven't built one for the LS yet.