You wont get more power out of a higher octane gasoline unless you manually advance your timing (i.e.: rotate your distributor for more timing advance).

This might be good for about a 3 hp kick... but it means that you can't put in 92 anymore, as it'll cause running problems unless you return the distributor to its stock advance.

In other words, it's more trouble than it's worth. Higher octane will have a better detergent effect, though, and you can use it for "italian tune-ups", but that's about it.