Coughing, backfiring ... *UPDATE*

Go back to the basics. Check your wires for orientation, it's easy to mix them up. 18436572 clockwise around the cap. Passenger side of block is even 2468 from front to back, drivers side is odd 1357 front to back. Double check your air gap on the reluctor, should be .008 checked with a non metallic feeler gauge.

If the cylinders aren't firing properly and not burning the gas you could smell raw fuel. It could be running rich as well.

What are your cam specs? Not that it would help me much, but might shed some light to the more knowledgeable here.

Try a little less initial. I have my initial at 16* with 38* all in by 2500 rpm.

Are you running a ballast resistor? Probably not your problem but you can bypass it briefly to see if there is a difference.

What about your coil, do you have a spare to throw at it to see if that changes anything?