Looking to get new sc pulley. which one is going to be easier to install? which is going to be more efficient? and which one is going to give more power? also you do not need a new belt for either correct??

thank you!
DJF

 

The install for either pulley will be pretty much the same.
As far as power, not sure what that 1% equates to horsepower and torque, but the 17% may create a little more heat.
I know you can use the stock belt with M7's 16% not sure about the Alta.
I say go with M7, the products and customer service are top notch.

Try doing a search for either pulley, you'll find a bunch of info on them.