(Shorter edition) I replaced wires and plugs, but had to use one of the used wires(longer than supposed to be) for the plug under the alternator, now i have a constant stumble from a stop(around 1000-1500 rpms). What is the cause of this?

Well i had the weekend off from work, and i went and bought new plugs and wires, Standard wires and Ac Delco Platnium Plugs. It took an amazing 9 hours all together, with taking out the starter. It was my first time doing the plugs and wires on an LT1. I was able to replace all the plugs and wires except the wires running to the plug closest to the Alternator on the passenger side. I couldnt get the custom fit wire to reach the opti so i used one of the old wires ( the one that looked in the best condition), and ran it to the opti. I also changed the oil (put in Mobil 1 10w-30 synthetic), and replaced the thermostat with a new 180* thermo from Stant.
After this i drove 100 miles car seems smoother accelerating after 1500-2000 rpms, but what i did notice was that there is a stumble around 1500 rpms when i push the pedal fast from a stop. But if i ease into the pedal it is fine. I had this problem before, but that was when the car was cold and just started. Now it seems it does it all the time, even when the car is running around 190ish degrees. I even drove about 100 miles constant and when i stopped at a toll booth then started to push the gas it stumpled and fell on its face, then regained rpms. Is this due to the Longer wire i put on the first plug on the passenger side, does that effect anything? Im totally lost and this little stumble is killing me since I live in the city and im always stopping and going. Can anyone please help me?

 

Make sure the wires arent arcing to anything, it seems to me that if the old wire was worn enough, it might be arcing. I would check that first, then go from there IMO.

 

I had a similar thing happen to me, one of my wires toucked my headers and melted through it, I had a spare in my truck and put it on, i belive it was for cylinder #8 and i needed it for #2. Anyway after i put it it my car was ******* gutless till about 1k then ran smooth, i put a proper wire on later and had no problem.