Cylinder head mods for Blowers

That's the thing about roots blowers - by their very nature they overcome some of the inherit "limitations" you'd find in a naturally aspirated engine. To quote from the book, Street Supercharging p. 105 (note:this is street not racing): As far as port size, port shape, and valve size is concerned, as long as they aren't so small that they will strangle the blower's boost, leave them the way the are.