Bishop,

Although I'm not a SB genius, some things come to mind;

Make sure no ballast resistor ahead of HEI.

Verify firing order..#1 drivers side front, and CW rotation of distributor.

Lifters (hydraulic) were pre-filled and roughly set before running engine.

Carburetor is getting proper fuel and has approximate initial idle settings.

If the engine will start at all, manually adjusting the loose distributor one way or the other should make a difference in the way it runs. Are all your vacuum ports either capped or have hoses attached. Good luck.

Stuart