What fuel is best?

It does not need 93. However, you asked what the best fuel is. Probably something like Cam2 118 leaded or Sonoco Supreme. Those would be "best". A stock 225 does not need "best". They are 8.1 compression at the most, regardless of what they were rated. They always blueprint out less than the rated compression ratio. Even if they didn't, 8.5:1 in no way shape form or fashion needs 93 octane fuel. You will be wasting your money. I would use 87 and run a good lead substitute and you should be fine. I also run an ethanol treatment in mine as well.