I was under impression that my JE pistons were the ones that are 10.8:1, but I checked the part number on my invoice and I guess they are the 10.1:1 flatop pistons with 2cc valve reliefs.
My block is decked, and if I use a .40 head gasket with 57cc heads, around what would my compression be? Thanks

Also, are flatop pistons a good choice for a motor thats mostly naturally aspirated, but may be sprayed later? Thanks

 

your compression would be around 11.88564 depending on your deck height and inside diameter of your head gasket.