Just a heads up ARC had just gotten in the HEMI flattop pistons. they are lighter than the dished ones and a more modern design with thin rings. I ordered two and they said it comes with rings. Here is the post from Bob's site
We now have the flat top Predator pistons/rings in stock. Part (#DJ-1285PH). They are not currently on line but should be in a few hours. This is the original flat top that comes standard in the Hemi head Predator engines. One thing we found out after we received them in was they are LIGHTER than the dished piston we currently carry. Flat top weighs 138.5 grams and the dish piston weighs 150.5 grams. This flat top will work with any of our stock length and .020 longer Billet connecting rods for the Predator engine and uses the stock wrist pin. (6254-6256)
We now have the flat top Predator pistons/rings in stock. Part (#DJ-1285PH). They are not currently on line but should be in a few hours. This is the original flat top that comes standard in the Hemi head Predator engines. One thing we found out after we received them in was they are LIGHTER than the dished piston we currently carry. Flat top weighs 138.5 grams and the dish piston weighs 150.5 grams. This flat top will work with any of our stock length and .020 longer Billet connecting rods for the Predator engine and uses the stock wrist pin. (6254-6256)