73 duster wont crank

hi everyone i have a 73 duster and i redid the exhaust and intake manifold and rewired the light switch and windshield wiper switch and when i went to start it it didn't even crank at all. so i replaced the starter relay even though it was only a month old with maybe 5 hours on it and i replaced the neutral safety switch. does anyone know how i can fix this? when first tried to start it it would like kind of bang like it was the starter and one time it clicked rapidly like it was from the starter. also all the connections are good and i'm able to jump the starter.