alt pulley question

[Vicious805cobra]

I'm about to pull the trigger on a few parts I need to be done with my kb set-up. The kb is currently set up with a kb 3.5 upper, stock alt, and metco stock sized pulley ring. Question is do I need a diffrent sized alt pulley for my set up?
:beer:

 

[MWoods26]

The size of the lower is the only one that has any effect on the alternator. If your lower is stock size then no need to change from a stock alt. pulley. Even a 2lb lower is fine with stock alt pulley. Once you get into 4lb and bigger you need to change the alternator pulley.

 

[X3FBrian]

I've read that even stock lower it over spins the alt. I'm curious on this as well because I have a 3.2" alt pulley I'm about to swap onto my new alternator.

 

[Vicious805cobra]

The size of the lower is the only one that has any effect on the alternator. If your lower is stock size then no need to change from a stock alt. pulley. Even a 2lb lower is fine with stock alt pulley. Once you get into 4lb and bigger you need to change the alternator pulley.

That's what I was thinking, I've searched and just come up with old threads hear. Thanks you just saved me $54 on a pulley :beer:

 

[MalcolmV8]

The size of the lower is the only one that has any effect on the alternator. If your lower is stock size then no need to change from a stock alt. pulley. Even a 2lb lower is fine with stock alt pulley. Once you get into 4lb and bigger you need to change the alternator pulley.

I've read that even stock lower it over spins the alt. I'm curious on this as well because I have a 3.2" alt pulley I'm about to swap onto my new alternator.

The alternator is already over spun quite a bit from the factory. I have the stock lower on my car and put on a 3.2" alternator pulley after my stock alternator burned up with only 30k miles on the car. I see 14.6 volts at idle with the 3.2 pulley.
No head lights dimming at idle at night or any of that.

 

[cobracide]

I have had a 3.5" alternator pulley (rated for a 6# lower@stock speed) on with a 4# lower for over two years, no issues.