I have read a couple articles about adding a throttle body spacer. with claims ranging from more HP to better mpg. I was surprised to see these advertised kits range from very inexpensuve, to somewhat costly ? Has anyone installed a throttle body spacer on their 4.7 motor, and if so, did you gain any improvements in performance or mileage after doing so ? The kits are advertised as simple bolt on units with everything included,

 

I would not get one. Have not had one but I say for the price they are not worth it. Have talked to few that have had them and they say they didn't work. Plus I see it this way you put that in there and now the air has to travel more distance to get to engine, how can that gain power or mileage?

 

the intake manifolds on 4.7's are already very efficient, I dont think it would be a very smart area of the engine to spend money on. besides throttle body spacers are pretty much proven not to work on fuel injected engines.

 

Throttle body spacers only work on motors using carbs or throttle body injection (tbi) intakes. Do a search on this subject in this section and you will find many interesting threads about this subject.