Timing is pretty much fixed. It's all controlled by the PCM, and the distributor has basically nothing to do with it. Just doing wires and plugs isn't going to throw it off, and the timing chain would have to be REALLY bad before it would slip a tooth or so. (in fact, if it was that loose, you would have been having problems before now.....)
Check the plugs, see what they look like. Make sure cam and crank sensor are plugged in good.