I was wondering if I put performance pulleys on my 03 blazer 4.3 will it make a difference? If it does make a difference, will it hurt my engine in the long run? Do they really work? Thanks

 

It will make a slight difference. You may experience some dimming headlights at idle since you are underdriving the alternator. The temperature might climb a little on the gauge. Yada yada, all of these things are intended. If you run high power stereo, it would be a good idea to invest in an Optima battery while you're at it. Its not going to hurt the engine, it might run a little hotter. But an easy fix is a 180 degree thermostat if its really that big of a problem.

I'd say its worthwhile given the ease of the job. But not a good idea if you have heavy duty subs (of course an optima battery and a big-3 upgrade will solve that)

 

I would recomend an odyssey battery other than the optima. They are smaller and put out more power. Optimas quality is starting to lack aswell.