First time start - no go

Hi everyone,

I've gone through all the first time startup procedures and have been getting ready for this day for almost a year since we bought the car. Battery fully charged, coolant, gas in the bowls, primed the oil pump, turned it over and a couple of cylinders seemed to fire, some back fire out the carb, but it wouldn't catch. Adjust the timing, tried again. No joy. Further timing adjust made it worse. Put is back to the starting position. Even tried backing off the other direction. Nothing. Checked plug wires, coil wires, nothing seems to be getting hot. I don't want to keep turning it over and flattening the cam. Measured the voltage at the coil and it's only 4 volts, should be 12 right on both terminals or between them? Any help or advice would always be appreciated. You guys have already been a great help getting me to this day.

Oh yeah, 1974 Dodge Dart Swinger with a 360 LA, a few mods were made like a purple cam, headers, Carter 650 carb, nothing crazy. I didn't do the rebuild, bought it that way and it's never been started since.