This looks to be a wide deck cylinder. Oversized pistons need to be mated with other oversized pistons to keep all the recip parts the same weight. If you only have one cylinder that has an oversized piston, then it could cause vibration issues. I think the oversized piston weighs about 15 grams more than standard and that is outside the range of recommendation for Lycoming at 2 grams. Someone else on here may have actual weight data on hand to back up my claim?