I also am thinking of the underdrive pulleys, and the Efans as well, is there anyone that has done both? If i go through Troyer Performance it will cost about $700 for my 05 5.4 F-150 if i get both. So if i got just one which would be the best gains for the money? the fans are around $430 and the pulleys with the belt are about $260. Or if there are any improvements in that price range let me know! Thanks

I got my set in on Monday and im having the underdrive pulleys put on thursday morning. ill let you know how i like them:thumbs up yellow:

sweet thanks!

sorry about not responding. I had them put on and i like them pretty good, Got my truck to bark the tires after they were installed. Dont regret buying them.

cool! thanks for the update! which did you get?

The troyer underdrive pulley kit.

cool, thanks for the info!