My Gen II Hemi starts to break up in the 6000-6500 rpm range. This was not the case originally but has started in the last year or so. It only has a few thousand miles on it. Build is 4-5 years old. Cam is a Lunati hydraulic roller: 231/235 @ .050"; .535/.550 lift. Springs (recc. by Lunati) are installed at 139# on the seat and 325# open (per their recommendation). Valve gear is all stock. Does that sound like enough spring? Or any other thoughts are welcome. Thanks.
