first of all u need to know what ur rpms r at elevation. If u r 7700-7800 then go to 3 ,if ur 8000 then u could go up to 2.Every clicker up is 200 rpm.Most likely u will have to b at clicker 3 or 4 maybe higher.
Yeah like it was asked, what sled? With an MXZ, it won't matter what setting you put the clicker at.
If its a 800R ptek, you want to be in the 8100-8150 range for RPM. Don't go over 8200, the power drops off. On the trails, its not uncommon to be revving high, but there is no load on the motor. Most people are concerned with peak rpm when climbing and holds those rpms while making good track speed.
A little more info on what you are trying to achieve will help people offer the proper advice.