Hey Folks probably a long shot but I thought id as first. I recently had the head lifted on my car 2009 F6 310. While I was there I changed to atomic valve springs , atomic head bolts and gaskets atomic harmonic balance r etc. so no real performance enhancing items. When the head was refitted the car seemed to have a spit / misfire in the mid to high end RPM range. I have changed spark plugs / injectors / had a retune / and the miss fire remains. If any one has experienced anything similar would love to hear from them Thanks in advance