I use 87 as recommended. Higher octane is for higher compression ratios. Since the Z is air cooled, I feel that it's best to run the recommended 87 in it.
So any advice as far as advancing the timing to effectively run 93. I can with the PCV and can map the timing out.Run 87. Run 89 if you wish. Wont make much of a difference at all. Ive been down this road so many times. If you get a fuel controller and it states use 93, then use it. I dont think the stock ecu has a way to advance the timing enough, (especially with no knock sensor) to make 93 useful.