The 4.0 Ford OHV starts at about 160. It has 19lb injectors. And no, injectors from a J**p will not work, you need Ford 4.0 OHV or 5.0 injectors. Keep in mind, I still run stock injectors with my setup, though I will probably upgrade after installing the N2O. When you swap injectors, you do not need a new computer, but you do need a new MAS.