It seems that somewhere around 140k - 180k miles the 2.6l engine blows the head gasket. If I were to pick up an engine and rebuild it from the ground up, is there anything that I can do that would reduce the chance of blowing the head gasket? Is it that the engine isn't cooled at the same rate around all cylinders? Can the water flow or air flow around the last cylinder be improved? Are there obstructions in the casting in the water jacket?

I liken it to a problem a friend of mine had with an early '60s Porsche 356... one of the cylinders was notorous for not getting adequate air flow and roasting that cylinder. Granted - that was an air cooled engine though.