What you thinking dude....................only in extreem conditions is a medium plug used in a small block engine for any % of fuel. If you don't know that a small block disapates heat much to fast to run medium plugs then you don't know much about this hobby. To get the HP on an engine why would someone put in a cooler plug when they raise the nitro % percentage, that would defeat the whole reason for putting it in the first place. Please don't spout information you have no knowledge of because it misleads the new people[>:]