Homemade heads?

You could machine some heads out of solid blocks of aluminum, if you had the machinery and talent. It is being done by top engine builders, but the price is way out there. I can't say I've ever seen heads made from weldments. I believe the combustion pressure inside requires amuch more robust construction than a bunch of smaller pieces welded together. Along with the intricate shapes of the passageways inside, (don't forget, you have air/fuel running thru them besides water and oil passages!) plus allowing for room for the valves and all the hardware that attaches everything... it isn't a job any novice, or even most experts is going to be able to handle.