Put a tornado in with the spacer and you will see 10-15 HP and better fuel mileage.
Oh wait, that's right, the tornado doesn't work. It needs that certain mojo that a spacer has.
Those spacers do not help. I believe it goes back to carburetor days when insulating spacers where used to raise the carb height and keep the carb from heating up and boiling fuel in the float bowl. It helped on a carb. The added height gave a short amount of extra time for fuel vaporization and kept the carb cooler. But since there is no fuel at the throttle body, and the short amount of added space doesn't do anything measurable for the throttle body, I believe it is a waste of time to bother.
Build a heat shield, clean the TB, optimize the TB, clean the UIM and LIM. All these are proven performance enhncers that are inexpensive. Throttle body spacers fix a non-existent problem, imho.
