With a stroker kit you basically need to change the whole engine. Since you are increasign the volume of air being compressed you need to either run a higher octane fuel, or start using lower compression pistons. Since it's hard for us to run a higher octane fuel....(we already have to use premium because of our C.R).....that leaves us with the option of replacing pistons as well. I can see where this becomes a very expensive rebuild.........maybe not as much as they are asking though!