long time listener first time caller.
Have you seen any of the Richard Holdener videos on the old YouTube about this motor ? he was a tech editor for hot rod / motortrend and has done loads of vids covering stock ls turbos etc.
playlist below from youtube for like 30vids going through a ton of options on the L67 3.8v6, he even built a twin charged one at some point. Made around 600hp at the crank with a gt45