We'll assume you're using the heads that it was produced with and they, nor the block, have been cut. If that's true, 87 octane is fine and desired. If you're running small bore heads or your stock heads have been cut or the block has been decked, that's a different story. We'll also assume you have not by-passed the rev limiter.
On a stock engine 87 octane is just fine. Using higher octane is a waste of money and a loss of horsepower. You really don't gain anything but bragging rights.
