I watched this about 4 times while my heads where getting torn down and cleaned.
Then I used one harbor freight part number 96826 my carbide bit set for steel and aluminum. (I have a edlebrock performer intake) I port matched my intake and exhaust.
I did not do as good a job as power block for sure, but for my jeep its fine. Even though my work doesn't look the best, It's amazing how much metal I removed in a few places. Some as much a 1/8 of an inch was removed.
I chose not to mess with the combustion chamber. For fear of messing up a valve seat.
The steel was easier to work with, but took allot longer. The aluminum was harder to work with but was done in 30 minutes. The performer intake to My surprise needed a good bit of porting to match up well.