Hattiguy is right! If when you do have that #14 head off, look very carefully between both intake and exhaust valve seats, also the precombustion chamber, this is where hairline cracks can be found in the cast aluminum of over heated #14 heads. They can be found to be present on any one, or all, cylinders. Also don't be surprised if you find deep corrosion pitting, (caused by use of standard green antifreeze) also can render any number 603 head useless...............Good luck........BB