Underdrive pulleys?
 

Is it possible to get these for a 3.8 engine. I've seen them for other vehicles. Anybody have any info they'd like to share i'd appreciate it.

what does this do?

more hp?

I know where you're going with this, and no this is not possible. The 3800 (to my understanding) an interally balanced engine that could not handle a smaller underdrive pulley. Just gonna make everything work harder than it has to.

Underdrive pulley do give you more horsepower but make your engine work harder. Unless it is the same size but less weight. But not to often will you find companies that make pullies like that. I would stay away from them. Know to many people including myself who killed their alt. cuz we changed out the pulley.