Picture of 340/360 head porting....Mistakes?

skrews said

The valve seat profile and valve shape along with the forms1/4 inch above and below the valve seat are everything.

Click to expand...

Absolutely 100% fact. You can spend a boat load of time and money just sorting out that 1/2 inch. And, you can spend a boat load of time and money on that same 1/2 inch and lose your ***. Still looking for mine.