What plugs did you put in it? I'm curious, but for your problem I really don't care what they are. Replace them. Quadruple check the gap 14 times. Make sure not to bump them when putting them in. Straight into the hole, if you bump it, check the gap another 97 times. On each plug. If that doesn't work, replace the plug wires and be RELIGIOUS about wire spacing. At no point EVER should one wire touch another one. EVER.
Do this. It may not be your problem, but I scratched my head for 7 MONTHS and my fvcking plugs were the problem. Then last fall I was befuddled for 2 months and replaced what appeared to be perfectly good AC Delco plug wires, and voila.
Delphi plug wires, and a GOOD plug. I am actually running Bosch +4s just for the reason that you don't gap them.
Do this. Deteriorating driveability is ignition related. A fuel pump gets weak, not strong and then weak and then strong again, IF all your wiring is good and clean. A too small or too large plug gap can cause fouling that continually gets worse, and a burning spark plug wire will continue to lose voltage and get worse.
Start with the small things, but do them perfectly.