My 505 stroker was running rich, but figured I'd rather have it a bit rich than on the lean side during my initial miles and until I could get it on the Dyno. Even though it was rich it was running well. Recently however it developed a back fire. It pops now and then, and you can hear the exhaust drone coming in and out as the cylinder kicks on and off. I swapped out the plugs thinking I fouled one out, but it was still doing it. I looked in the engine bay last night and the plug wires looked like a luminescent show around therm. I'm assuming my next step should be to get new plug wires. Should I go MSD again or a different brand?