440 wont start

Popping and banging?

Try a different coil.

Any chance you whacked the ballast resistor on the firewall
when pulling the driver's side head off? Try another one anyway
(after the coil first).

Both of these 2 minute-to-change items could cause the symptom
you describe.

If one of these works, I hope you don't get a welt in the middle of
your forehead from smacking yourself!

Good luck.