First off, the camshaft change will probably NOT require a fuel injector swap. Check with the camshaft manufacturer to be certain but that is rarely the case from our experience. What will require a fuel injector upsizing is a power adder installation like supercharging, turbocharging or Nitrous Oxide Injection. We do not offer fuel injectors so the power adder company will recommend the size of the new fuel injector required. If you do change the injectors, we will want to know the type and number of Oxygen Sensors that you will be using to make sure our harness is correct for your application. It would also be important for you to know if the new power adder/larger fuel injector application is emissions compliant – that information is always valuable to the vehicle owner. Also, investing in a Wide Band Air/Fuel Ratio Meter is a great thing to make sure your vehicle is operating as efficiently as possible.