We were thinking of running a 12 row head on our 9650 sts.  Sounds like we might run into trouble because of the weight.  It would either be a 12 non-chopping Drago or a JD 1293.  The Drago is 700 lbs. heavier than the Deere. Our combine has 63 mm cylinders.  How big are the heavy duty cylinders?

 Any similar experiences that might help us out?

 Thanks.