Help with Underdrive pullies!!!

[gooch06]

Hi I have a 1990 LX 5.0 with the Ford Motorsport Underdrive pullies. I wanna upgrade my Alternator to a 130 amp. Will the alt. work with the underdrive pulley? A tech from Powermaster said that the underdrive pulley has to be smaller than the stock pulley I took off. Is this true or does anyone know if the underdrive alt pulley is smaller than stock?

 

[sgarlic]

It depends on what brand underdrive pullies you get.. on most, the alternator pulley is pretty close to the same size as the stock one is. However, on the 3g alternator, the pulley is a little smaller than on a regular foxbody alternator anyways, so it probably wouldn't be worth it to swap it out, (unless you have serious charging needs.)

 

[DouglasOhio]

When it comes to underdrive pulleys, the alternator and water pump pulleys are actually bigger than stock. The crank pulley is the one that is smaller.

 

[gooch06]

I'm confused will a 130 amp alt work with Ford Motorsport Underdrive pullies?