I have a 1995 Bronco with the 5.8. I have installed a K&N filter and a Flowmaster catback. I am wondering if anyone out there has tried the undersize pulleys and the throttle-body spacer kits for the 5.8? I asked my local Speed Shop and they didn't know much about them..they like to drive in circles alot and run into each other. I am primarily interested in improved mileage and power when pulling a trailer. I live in the desert so overheating would be a concern! Any suggestions appreciated. Thanks

 

Throttle body spacers for your 5.8 won't do any good. Underdrive pulleys may work but you might have problems with cooling or alternator charging issues. Some people get them to work fine and then others say they are crap. I got some pulleys in the past but at the last minute I decided to return them and I'm glad I did.

 

The fact that the local performance shop doesn't know much about them should be a signal right away.

Personally, I've never messed with either because everything I've ever heard was negative. Throttle body spacers have always seemed to me to be like the proverbial "snake oil". From what I understand you could change your oil twice as often and do better for your performance than to toss your money into one of these things. As for undersized pulleys, my question will alwyas be, what will a computer controlled engine gain from them? The drag from the belt-driven components remains constant regardless of the pulley size. They might allow you to run a lower idle speed and not lose the effectiveness of the accessories but when the computer decides what the idle will be, what do you gain?

 

I am with both these guys. waste of money.

 

This is more of a question to your question.My Bronco is a '95 with 5.8L auto.I have been wondering about putting in an electric rad fan.Has anyone tried this? What gains if any??

 

if you try a search an electric fan upgrade/install has been talked about and done alot.

 

Under size pulley's can work, but they're a bit controversial, and definitely not for people with upgraded stereo, and stuff like that. TB spacers are mostly snake oil, though they may actually help a tiny bit with carburated cars. However, at $75 or so (a price I've seen) they're a definite no-no for EFI cars.

 

I appreciate the thoughts it always helps to bounce ideas off other enthusiasts...take care.