I was told that the piston grade could be found on the block.....now umm where on the block is the stamp...... I just need to know what grade DET's to order there are like 3 options

the grades are stamped on the deck of the block(head side up)
If your old pistons are clean enough, it is also stamped on them.
You will see a 53J and a number all by itself that is the grade. (on a N/A DE) The turbo pistons are the same (I Know our GTiR engine has pistons stamped 54C and then a number all by itself)

Is that to say that all sr20DE'z have a the same piston grade requirements??? there is grade 1,2 and 3 availible