how much gain should i expect from them? it's a set of crank and alternator pulleys, and the belts.

 

i have the crank pulley and i would say it freed up about 10 hp. i dont' know if anyone has ever dyno'd after installing the pulley.

i wouldn't add the alt pulley. unless you have a larger than factory alt.

 

Guy that used to own a local shop dynoed after the pulley. I think he got a solid 10-11 HP.