Wow, we pretty well killed his thread.... innit there a smiley for that....
Oh wait yea there is:

Here's one for the V10 that makes all kinds of ridiculous claims:
http://cgi.ebay.com/ebaymotors/ws/eB...m=260436877940

The reason why these things don't work is that these trucks use a multi-port injection system. The gas is sprayed into the intake tract right outside the intake valve. These spacers are mounted at the TB. Anything they may do to the incoming air stream is inconsequential once it goes through the intake manifold to reach the injector. Now, if these trucks used throttle-body injection systems, these devices might have some merit.