i just pulled my head off and want to know what pistons are in my car if they are stock or not the numbers i found on them is 56-026 then below that
5997612 0.50 then on the header side 040 below that looks like ITI below that 0336 any help would be great

1

 

I have the same pistons except for 0.75 mm so hat pistons are they? Speed pro?

 

hate to drag up an old thread,but I have the same exact ones and wondering if anyone had info on these