Some shops still are sticking with outdated procedures even today. The practice of machine large amounts off the deck is not needed, as the readily available piston selection. This selection did not come about by accident its due directly to building the engine correctly vs hacking the head to hell and back. ( I am using the term correctly a engine builder would know what is correct and what is not) as when that happens you are making the push rod geometry worse and that is just not the way it should be done. Taking a short cut is silly when you look at the amount of money spent on these bike to start with.
Use of a piston or just a thinner head gasket and the correct cam will yield great power .. I can prove that all day long with real world testing. Dyno sheet after dyno sheet, or we can post up ET slips as well .. Either way I have the proof and that is what its about. Anyone can type that "X" cam or "X kit" is the way but can you back it up. Can you show the real world back to back testing ?
Or you can have a set of these to use for door stops. Just an example of heads that where "milled" to increase the compression. It had the compression however intake fitment was not working, ex was sitting low and needed more work to clear brake pedal and cam cover. Push rod angle was increased dramatically, All for what???
Simple bore and hone with a set of pop up pistons, SE, Mahle CP . That would have saved this customer from buying a new set of heads. Cost to fix out weighed new heads. Not going into the lack of power they produced, on not one or even two but three tuners..


Here is a 255 tuned vs our cam tuned. I did nothing but install cam and retune. Some heads flow better than others and ex is a key player. However you can see that the two cams are both working great down low and then one cam pulls away from the other. Peak numbers aside as you are dealing with stock parts and ex system that I had no choice on. You can see it does very well. No loss of low end cooler running and power that pulls out. I have several 570 vs the 577 back to back and the 570 does not do very well compared to not only our cam but many others. Its no the worst but by far not the best choice either. Good luck on your set up I am sure if you get a game plan together you will end up with great results.
