Here's a 906 head I ported. Port on the left is almost done, port on the right is basically stock. After doing a few dozen sets, on my second trip to the hospital (at a cost of over $1200) to remove metal shavings from within my eye, I decided a career in head porting was not where I was going to make the big bucks. In case you're wondering, yes, I wore safety goggles. However, when you're dealing with eight million tiny metal shavings, a few are going to get around the goggles. Not sure if this would be of interest to the average person, but oh well.