Be really careful ,I dont take Any heads to napa any more to get them checked , They put the head in an oven and burn all the crap off of em. I took 3 different Mercruser heads to the napa store and all 3 of them were cracked they said and they showed me where and they were right, the problem, they cracked them in the oven they heat them up real hot and when done set them out to cool like a pie and they crack the valve seats, and between.
I know this because i checked out the last head really good and when i got it back it had 3 big cracks in the seats that werent there before. Just a heads up. dirk