Change spark plugs hard to start

[1974dodgecharger]

Changed the plugs out tried to start but didn't. It would turn over then die out mediately then I decided to give it more gas before cranking it well I kept the gas pedal down to crank and viola it started.  It revs a little high now.

Does anyone know what it means the initial hard starting now the high rev? Now she starts fine with no pumping of pedal just fires right up.

(Stressed me out for 30mins knowing it would not start  it's a 383, Holley 750)