Ok guys help me out here..I recently put new LT's and O/R h with flows out back, car sounds nice and angry..but I noticed tonight that there is a hint of sputtering in the exhaust, like the car is slightly missing. The sound is only at idle and there is a slight vibration to the car at idle. Upon inspection I found my balancer is all done and will replace this week, but what might cause the sound. Idle is rock solid and car pulls strong and clean so I don't know if maybe the sound is normal but more obvious due to the fact I have the open flow exhaust now???? Also I'm running .54 (or .054) gap on my plugs..car has stock longblock and eldelbrock rpm uper and lower..should I close up the gap to something smaller.