i recentley had my z28 dyno tuned and when we looked at the air to fuel ratio we noticed that around 4200rpm my fuel mix got really rich and when we adjusted the mix we ran it so lean even the tuner was shocked he had never seen the numbers we used before so does anyone have any ideas why the car runs so lean i have a new cam head work and bigger valves but stock injectors we checked the fuel pressure and it was fine i think stock injectors are 32lbs but i am not sure so can anyone help