I'm in the process of replacing a damaged piston, and in the shop manual it says to replace with same grade piston that is currently installed, but does not elaborate on the subject. I'm looking to just replace the one damaged piston and not touch the other 7.

Any help would be greatly appreciated.

 

Yes, The piston grades for each cyl is pinstamped on the front of the block. Look at the flat machined area on the front of the engine block which will be below the rightside head deck above the large freeze plug and to the side of the waterpump cavity...behind the front cover. You will see a series of 8 numbers in a row stamped on that flat block surface. the first number in that series is cyl #1 and the second is cyl #2 etc right through cyl #8. Each of those numbers will represent the piston bore grade for that particular cyl. So if the first number is a 2, cyl number one is a grade 2 piston and so forth. there are three grades of pistons 1,2,3, Usually #2 grade was the most common. so if your cyl #5 piston is bad. Count to the fifth number in that series of numbers and whatever that number is will be the piston /bore grade #

 

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