Does it turn over?
Have you checked ALL of your ground connections from the battery to the frame and block? Ground gremlins are a major source of problems and are easy to fix.
Are you using ethanol gas?
Do you have gas at the carb? Have you disconnected the fuel line at the carb and pumped gas into a bottle to see that you have a good stream while cranking the engine?
Have you checked for spark?
Why did you replace the distributor? Is the new one installed correctly so the timing is right?