miles per gallon. I have a set but haven't done anything w them yet. You have a closed chamber which'll give you more CR plus quench if you build for it (I would & definitely on a mileage 318 build). Did a little reading on them & bowl hog (forgot the angle) and going from the 1.78 to a 1.88 valve was recommended & mild porting/deburring is always beneficial

live every 24 hour block of time like it's your last day on earth