electrical problems, cranks and start briefly but won't run

[72restocuda]

1971 340, Auto trans, new harness, new coil.  Just put my engine back in after a 3 year restoration. It ran great before
Overall I thought I did everything right primed oil pump and witnessed oil coming through its passages - set to TDC on compression stroke,- used compression gauge -approx 140. backed off 10degrees, made sure oil pump drive gear aims toward cylinder1, put distributor in. Checked pickup on distributor before installation, good ohms (270), makes voltage when running in drill(.200V). 0.5 V at grey wire from harness going to dist. 12 V at ECU blue and green wire when disconnected.ECU grounded, extra ground wire to block installed here. Have spark at #1 cylinder. Starter relay - ground at brown wire, +12V on yellow when turning key to crank position.  5 and 1.2 ohms at ballast resistor. Cranks easily, fires then stops, immediately, I put fuel in the bowls, dripped some fuel into carb before cranking. Still not running past the initial fire.  Could the ballast resistor still be the prob despite getting good ohms, not getting 12V to system in run position? Any thoughts, thanks

[DeathProofCuda]

Is it dying when you are releasing the key from the "start" to "run" position?  If so, sounds like the ballast resistor.

Have you tried having someone continue to drip fuel or spray starter fluid into the carb after the initial fire?

[72restocuda]

I will buy a new resistor but the ohms is reading fine, will have help to continue to drip fuel into carb or use spray starter fluid

[72restocuda]

not enough fuel in bowl I think, its running now, thanks for responding on a Sunday
-Steve

[Bullitt-]

  Check for voltage (about 12V input 8V output) at the ballast resistor on the Blue wire with ignition switch in the run position, If none or extremely low voltage trace the Blue wire back to the ignition switch. It is not uncommon for a wire to not be seated well in the connectors. The wide flat connecter along the steering column seems to be problematic as well a the bulkhead connector.

You can temporarily jump the ballast to see if it is the problem

[pschlosser]

I will buy a new resistor but the ohms is reading fine, will have help to continue to drip fuel into carb or use spray starter fluid

The ballast resistor is bypassed during cranking.  If the engine starts while cranking, but dies once the key is released, then it seems likely it has something to do with ballast resistor.  

It may not be the resistor, itself, but one or more connections leading to/from it.  I agree with @Bullitt- to jumper across the ballast resistor to confirm.  By jumper, I mean short the two ends of the ballast resistor connection together.  This will only test if the ballast resistor is bad, it won't tell you if a connection leading to/from it is the problem.

[DeathProofCuda]

not enough fuel in bowl I think, its running now, thanks for responding on a Sunday
-Steve

Glad that you got it figured out.