I zero decked the pistons and ran .039 head gaskets on a 318 magnum and was shocked how much difference it made, more so at higher speeds. That was the only mod at first on that truck.

The injectors help more at lower speeds by atomizing the fuel way better, the ferd injectors have 4 splayed nozzles instead of the dodge injectors with one straight stream nozzle. The flow rate on both injectors is supposed to be the same.