[android 211]

If you don't know what you are doing with the die grinder you can spend a lot of time without doing much good. The trick is to not try to recontour the port but to improve certain areas. Streamline or tear drop all the valve guides. Knock back the pushrod hole bulge inside the intake port a little bit. Polish the exhaust port but not the intake port. Smooth the bowl area on both intakes and exhaust ports. If the exhaust seat was opened up for the 1.77" valve then make sure the bowl area was smoothed to take advantage of the bigger valve. This will take a couple days to do. Thats why it costs so much. Its worth 50hp supposedly.