Piston size?

Since my mutt was low on compresion (below 70) I pulled the head today.My cuestion is,the pistons dont have the size on them,should I assume they are standard(stock)? they do have a notch pointing forward. Any help would be apreciated so I can order parts. Not much play in the pistons in the bore,so I will put new rings and rod bearings,just need to know what size rings to order.Again THANKS

their will be a S on the top center of the piston for standerd , use something to scrach the carbon away real good , 10 on the top is for 10 over and so on , be sure to check the specs in the book with your parts ,and dont beleive the rebuild tag on the side of the block

Thanks Markcos! I will check again,I allready cleaned the top off the pistons and did not see anything,but maybe I missed it .Again Thanks for the reply!!

S, STD or no markings usually denote standard pistons. Make sure you hone the cylinders with a bar hone to deglaze and put a good x-hatch back in them. If you don't, you'll ahve built a large oil pump.

Thanks! Bar Hone? I have the 3 leg hone thing,is that the one? How many pases or spins do you recomend ? I dont want to take to much off,right?