Car idles nice then just quits...

[Shadoobie]

The stock ignition for the '79 is a marelliplex electronic unit that works really well. I would certainly replace the pickup if it looks bad and check the vacuum advance because it's probably done for too. I don't know if this is your only problem, but if the fuel return has been plugged in the carb swap you need to buy a fuel filter with a return on it and reintroduce that hose to the fuel system. My car had similar problems to what you are describing (runs fine, cuts out, pressure on tank) and those went away when I added the return back. Hope that helps.