well first off im new to this forum i have been building a 84 camaro in my garage. im building up a 383 stroker motor for this car. i have a new bottom end coming in the mail. so stripped my block. i was cleaning the block when i noticed on top of the pistons it say. "423NP .060" now i have not measured the bores. does this mean my motor is bored .060? the guy i bought the motor from told me all it had was a mild cam. he said nothing about it ever being bored over. im going to measure this soon. its not really a problem for me if it is bored .060. ill just have to send my STD ones back and exchange them.

 

yes that .060" usually means that is .060 over... If you get a pair of capliers it will come out to be 4.060" ....or if its a standard bore it will be "STD" A lot of times if someone didn't build the motor they don't really know whats in it. sorry you ordered the wrong stuff but you might want to take it to the machine stop first and make sure they can hone any damaged areas out of the cylinder walls with out increasing the bore. .060 over already is getting close to the point where i would be looking for a new block. I believe the max that recomended to go is .080 over.