Ive always thought as well that the mass produced heads got the cnc job because it was a mass produced. Ive never seen a head not respond to hand porting/blending as the finishing touch.

If one knows the casting well they can go past the so called safe limit that the mass produced cnc head.

With cnc becoming more the norm then not what about the motorsports that dont have cnc programs such as tractor pulling. Ive done many cast iron inline six heads that there will never be a cnc program.

As well as alot of the basics of head porting can help alot of heads to a point without a max effort and big costs.

Intake porting I think goes hand in hand with a max effort head porting job, this intake here in the pic is more or less maxed out runner and port wise and took a good amount of time to get there.

I like having the whole motor present to get the dead on exact port/head match which takes a good bit of time for just that process.