Hello,One thing I might consider is the Cam in a 6 is so long it's really hard to support the cam during installation, so it possible you damaged or push the center bearings out of position slightly when installing the cam. If the motor is out of the car,I either do one of two things when putting a cam in a long motor---stand the motor on end so I am dropping the cam in or leave the back cam plug out until the cam is in.Just some thoughts---Paul
