OK    so before i try to make one, i wanna make sure i understand this.  The spacer goes between the plenum and the throttle body,  or between the throttle body and the manifold?  ANYONE?

The plenum is a part of the manifold, the area where the airmass is a single volume prior to entering the individual runners after exiting the TB, so the spacer would be placed between the TB and the manifold.

Basically you are enlarging the plenums area, this helps low rpm responsivness and as you go to WOT.

Thanks Talon,  thats what i was thinking as well.

I just read Zaggys post from 5 years ago. They gained power and fuel economy with one. 2" is the optimal size.

I am working on lifting my air intake above my TB to make the air intake hose line back up after the body lift. I will let you know Free two tanks of gas if it make a diffrence on fuel economy.