been thinking about this as well when i put the engine back in, but is there a significant advantage for them on a "streetcar", making about 325hp? i know they free up some extra ponies, but if i do it, i assume the 3-pulley system would be best? and then how do you know what new size belt you will need, or is that info in the kit?

KAM

 

Pullies have caused a huge debate...many have fought and died in the pulley wars

In all seriousness, it has all come down to, this side says theyre not woth it, it kills you alternator, battery, overheats the motor, yadda yadda. The other select few claim they have no problems, felt a diffrence, more yadda yadda.

I look at it this way. Underdriving assecories is nothing new. It has been done for decades, and if no proven power gains were made then, it wouldnt be done today. A pulley swap alone will give you negligable power gains, but if you have a slew of mods already, then you may see more, and it couldnt hurt. However there are some details you need to know about. Do you have a superthumping system? Is you alternator old to begin with. Do you have a sound electrical and cooling system? Sometime items that are on there way out are finished with some simple modifications. Is your tranny stick or auto?

BTW, chalk this debate up there with "What will a 52-58mm TB do?" "Will I make more power with bigger injectors?" "Is a Stealth ram/super ram/miniram/larger runners gonna make me faster?" or "Will a chip (name manufacturer) help me?" That last one has started many a brutal wars, and still goes on today.
There is only one answer to all of these. It all depends on what you want to do and how far you wanna go.

 

gonna be staying relatively stock. no thumper for me. cooling system is good to go. i wasn't really looking for any additional power over what i will have, so it sounds like whatever gain would be negligible, and really not beneficial for me.

KAM

 

I am also considering underdrive pulleys for the next round of modifications to my 5.0 liter TPI. I have had considerable mixed opinions on their use. I searched the net and found some favorable reports; however, they were often written by the manufacturer. I did come across another article which mentioned cooling and electrical problems. There seems to be no concensus on underdrive pulley use. It comes down to do the increased horsepower "claims" outway the potential negative side effects.

 

A simple answer.....I have them, did they help? Not sure. Any problems? None.