the Truck injectors are 275 CC's, the 450's are for Turbo 4G63's. the ECU is calibrated for the 275's you would get way too much fuel. Also , the trucks 275CC injectors are High Impedance and the 450's are low impedance, so they wouldn't work in the fuel injector circuit. 2 reasons why the 450's cannot be swapped in. bummer for sure...