plenum spacer is theory would help the engine breathe therefore increase power but who knows. headers would also help breathe and push those exhaust gases out. the Z-tube is unnecessary for vortech setup because they have a piece to replace it. if you go with stillen you still need it

 

Awesome. Thank you gentleman. Last question... I have been searching for the better half of this morning trying to figure out which SC kit is the least noisy and the only thing I found was a thread from 2006. Being that that was 6 yrs ago does anyone know which one is today? I listened to a few on YouTube but most ppl only filmed at idle. I'm not a fan of the super loud whine that they have, I wld like it to be as quiet as possible.

 

superchargers are notoriously loud. the stillen has a loud whistle/whining type noise and the vortech sounds like a airplane turbine.

 

I found some videos on YouTube. The Vortech sounds amazing. The Stillen... Not so much. I'm not a fan of that loud whining noise at all.
Here is the Vortech. This might help the OP too. Sorry to thread jack. This guy is running it on a 5AT as well.