350 won't start-where should I look?

[72C10chevy4x4]

it's a 78 350 w/ the coil built into the cap (is that an HEI?).

The engine will NOT start. replaced the inline fuel filter in the 2 barrell carb-tested it and there is plenty of gas coming out (pumped it manually and observed it squirting in). Air-tryed placing a towel over the carb, closing the butterfly shut, partially open, no indication it wants to start. finally, replaced cap,rotor and checked spark at end of a plug-it's there, but not strong. not sure how strong it should be, but there is spark. will go back and replace plugs to see if that helps.

how about the spark-how much spark do you NEED to start the engine? gas and starting fluid in the carb made no impact on it starting and I hooked up the jumper cables to get it turning more quickly-still no dice.

help! I've exhausted all my ideas except for a weak coil-would like to know it's bad before buying another (is there a test?)

[72C10chevy4x4]

problem fixed. Turned out to be the plugs-as soon as a new set was installed, the engine started on the first shot. they were black and 'fouled'

[xtreme80]

You probably flooded it, and in the time it took you to replace plugs, it cleared the cylinders, and started. New plugs will definately help, but I doubt that it wouldn't start because all the plugs were that bad. If they were you got some serious problems there!

And yes, coil in cap is HEI

[72C10chevy4x4]

I would have thought the same thing about coming back later after flooding it. The problem was recurring-I had three different mornings of trying to start it, all with no 'luck'. The plugs looked to be gapped a little more closely then speced