If you did the work the same way you typed it.. you probably got the distributor out of alignment.
This is one of those jobs that is easier for me to do it , than type ( or explain) it!
But, Pull the number 1 spark plug, have a helper crank / bump the engine over while you hold a finger in the hole of number 1 and as you feel the compression blow past, stop cranking. Then with a socket & ratchet on the crank bolt, ease the timing mark up to TDC.

Then raise the distributor cap and verify the rotor points to number 1 ( or very close to #1). If it's pointing to # 3 or 6 then it's 180 degrees out., undo the clamp and reset the dizzy to point to number 1. Use a timing light, with the vacuum hose pulled off the dizzy and plugged. Verify the timing is to spec.

HTH.