Local guy here quoted me $350.00 to do it. I think he has (or had at the time) an engineer drawing of the LA engine that gave the exact placement of the passage. I think the biggest problem in drilling them is the length of the bit and the fact that it needs to be straight down to the cam bearing seat. He has a huge lathe that could chuck the bit and feed it out a little at a time to keep the flex out of the bit. I know he has done some similiar jobs before with good results. I thought about it but looked at the iron magnum heads with the 2.02 valves and decided it was a better setup. The magnum heads do flow a little better.