I have a 2001 Pontiac grand prix gt 3.8 Liter n/a and i recently changed plugs and put in ac delco rapid fires and msd 8.5mm wires. I had a lot of misfiring problems took out the ac delcos and put autolite iridium xp's in and everything was fine but what i wanted to know is if anyone noticed a difference when changing wires to msd.