I'm trying to find out will the pistons and rods from a det fit in a de and visa versa? I know that the compressions are different, but are the pistons the same size(bore and stroke). The reason being is that I'm looking to upgrade my De internals by going with lower compression forged pistons and connecting rods. Who sells them that would go directly into a US DE motor?

DET pistons work fine and you can buy them right here:

http://nismoparts.safeshopper.com/414/cat414.htm?482

Same bore and stroke.