Originally Posted by bracketeer
Just drill the lower 3 holes. They go straight in. The upper three holes are on an angle. If you buy aftermarket heads they tell you not to drill the upper 3 holes. Because you have a real good chance of screwing up. The lower 3 holes are the important ones. Its where the steam builds up under the siamese casting.
Most morons can angle drill the holes pretty easily, I have.....
I said MOST not all.