Homemade heads?

A guy CNC'd an entire slant head over on slantsix.org. cooling isnt that difficuly, just bore the largest tunnel you can in the head and cap and tap the ends. hemi head would be easier to cast as its runners can be straight in a cross flow head. You could make a flathead head with a 4" slab of metal. Not worth it unless you have the CNC and the time and the know how.