In a nutshell - YES. Both the 4G54 and G63B are known to crack through the combustion chambers into the cam valley or coolant galleries. But for some reason the 4G64 SOHC heads can warp to the point they bind cams and snap them in half. A characteristic that neither the 2.0 (G63B and 4G52) or the 2.6 experience. And the reason why #1 - I always recommend improving the cooling systems by installing an electric thermofan, and #2 - advise people to never mill a head true without first having it baked in an oven and pressed straight by a shop if it is out of spec.