I saw your thread on 3800pro:
3.8L Aluminum Oil Pan??? - 3800Pro.com Forum
The fact that the JY engine has an aluminum oil pan is not enough proof that it is an L32 (04/05+).
H-bodies have had aluminum pans on L67 since 2000.
What year/make/model did it come from?
If you are still unsure whether it is L67 or L32, a simple way to be certain is: does the fuel rail have both an inlet and a return fitting (i.e., two fuel lines=L67), or is it returnless (i.e., one fuel line=L32)? Another is: does the TB have throttle cables (L67), or is it drive-by-wire (i.e., sensor-driven=L32)?
Maybe it came with neither the rail nor the TB...in which case, post/host a pic of the supercharger, so we can tell if it is Gen3 (L67) or Gen5 (L32).
Maybe the */C'* not available; in that case, post/host a picture of the front cover crank seal (balancer would have to come off). I could tell by seeing that seal whether it'* L67 or L32.
One other thing; even if it is officially an L32, it is possible that it does not have the Series 3 internals, IF it is of 2004 vintage. In '04 GM was still using up old Series 2 / L67 internals, even if the engine was coded Series 3 / L32.
If you're STILL unsure, post/host a picture of the connecting rods (from underneath, with the oil pan off, where they are connected to the crank); then we can tell the most important thing about the bottom end--whether they are the old L67 cast rods or the new L32 sinter-forged rods.