I'd pull between 2-4* to be safe with 92 octane (even though it's only a point off), but you would probably be fine without doing so.
You do need 1 step (or 2, but 1 will work on a 100 shot) colder plugs. And I'd use copper plugs. I can't remember if it's platinum or iridium, but one of them has a negative chemical reaction with nitrous.
Most people will say you don't need to lower timing at all on a 100. I pulled 2* global from mine though. If you have an easy way to lower timing, I'd rather lose 10hp than be sorry.