My 434" small block was broke in and tuned on a engine dyno using Crate 98 race gas. After all the tuning we pumped the fuel cell and emptied the carb bowls and poured in a can of pump 93. After bringing it up to temperature it made 30 more hp than the 98 did. I thought it was a fluke or something went wrong with the computer so we cooled it down and made another pull, again 30 more hp.