I didn't look it up earlier because the original thread was over a year and a half old and I couldn't find that one (their search sucks) but then I ran across this one. the fastman throttle body shows what it should look like when completely polished up good. I had a 4.7 not the 5.9 so I couldn't utelize this on my truck. (it also works on the 5.2 liter ones too)
Be the change you wish to see in the world
OK a little fluid dynamics here you have a spiral of fluid (air) going into your plenum great now what happens when you try to split that single vortex into 3-4-5-6 or 8 ports. it breaks up into normal turbulent flow. therefore negating the effect. I see the vortex generators as a waste of time. TB spacers have a purpose that purpose is a slight increase in plenum volume adding a little top end power. I say don't bother with these snake oil type things. Stick to the things that really work.