With throttle body spacers being pretty much useless, what is the performance benefit of a modified throttle body? Hard facts are what I am looking for before I make a decision to go with it for my next mod. Pricey I know, that's why I need to know if the expense is worth it. Thanks for input.

 

You can try emailing the fastman to see if he has some info.

 

Anyone have any input on this? No response yet from Fastman, but has anyone done this mod and what gains in HP? Throttle response?

 

from what i read in other web site they work really well. just dont over do the size mm. most people have the 68 mm on the 4.7 and going to the 70 mm is good, but the 72 had some trouble with the engine. to large. if you have the 65 mm and bump up to the 70 mm its even more of a power gain.krc performance.com has a site with the tb and dyno runs. might want to check them out. i recently purchased the 206 cams for my 05 4.7. looking into getting these installed sone