Yes, head work is how to get the most out of a naturally aspirated engine. I know it's a little silly to spend this kind of money for 300 RWHP but I am not looking to build a rocket. I just want a fun car that sounds intoxicating. Especially after driving that LFA!!! I still can't get that amazing sound out of my head!
The engine is getting all the head work, larger cams, larger valves, better guides and valve seats as well as stronger valve springs and lifters to handle 9-10k redline. The throttle bodies were bored and the intake mani/exhaust flange will be port matched for everything. Lastly, the Nitto stroker forged crank and H beam rods. It should be one hell of an NA engine and if I ever do get the itch for more, I can just make a few minor changes and slap on a turbo for 1000hp
Not an RB but here is a pic with a head in which there is more room in the combustion chamber around the valves. See how the shape is more round like the cylinder instead of cut off just above and below the intake and exhaust valves. That area doesn't matter too much with turbo but it creates a dead spot that hurts the efficiency of an NA motor.
