Will burning higher octane gas help to kept the valves cleaner or is it just all in the oil?
What are the benefits of burning premium gas. All I ever burn is 87 octane in my AC 600 ZL efi
apv. Am I missing the boat by doing this?

A higher octane will burn "colder". I am assuming this is
a stock sled. So you more than likely will not see any
real benifits from the higher octane. I would just use
the 87 octane for your sled.
The apv's and your sled will like the best quality oil you
can afford. A/C makes oil designed for the apvs. I personally
would stick with that to keep your apv's as clean as possible.
These are the experiences that I have found.