Engine misfiring...after upgrades

I upgraded to 24# injectors, and a calibrated 75mm Pro-M Bullet.

I was having idling problems last night but that seemd to stop after I reset the computer.

Well I just go in from a 10min drive, and my average speed was about 50mph. I was in 5th most of the time, and I could feel the engine misfiring. It wasn't constant, but it had like 1-3 second intervals where it would miss.

When in a lower gear at lower rpms, the same thing would happen (that I could feel) when I was in 5th, someone in front of me slowed down to turn, but I stayed in 5th, and gas it more gas, and the whole car shook, it felt like the clutch was jumping, and the shifter was moving around a LOT. I take it the engine didn't like that. I came to a stop light and my car stalled, I had to give it gas to keep it running.

What could the problem be? Could it be my timing? I know my father turned it down for when I went for emissions, and I never changed it back. I figured maybe with the extra fuel I need to change my timing?

Please help, I'm all out of ideas....

I checked the timing, it was around 17*.

I moved it to around 10* it doesn't seem to be doing it as much, but it is still misfiring....Now what?

I did, yes.

I cleaner my rotor and cap up, and it tightend up one spark plug that was loose, clocked the MAF meter (I heard this helps sometimes) took it for a drive, and it seems much better, but I think it still might be misfiring, the bumpy roads don't help much when trying to feel it...and I set my timing at 12*.

I'm going to go for a drive and see how it feels now