1970 Chevy Nova 250 engine

Pull the coil wire at the distributor-ground it to the engine and crank engine over-do you have spark. No spark check for power at the coils power input terminal power there.

Could be the ignition contact point/s or the ICM if its an HEI

70 Nova has conventional ignition system with points and condensor. Major reasons for no fire are: coroded connections in distributor, bad points or condensor, poor adjustment on points (.017 to.019 ), bushings bad in distributor that do not open points properley ( common ).

Check the coil's primary and secondary windings. Then adjust the contact points as stated then use a dwell meter and adjust the dwell angle.