A bit more than you asked for, but here is what I know:
4.6L 2V engines used 19 pph injectors
4.6L 4V '96-98 used 21 pph (Denso injector- blah..ich!)
4.6L 4V '99, '01 if memory serves correctly also still used 21 pph, but they used a dual spray injector vs. the single spray used in '96-98, due to elimination of IMRC that was used on the earlier versions that have a runner valve that would close of the "secondary" intake port below 3250 RPM. Since these were Bosch injectors, I have access to the flow data of '99, '01 also if you need to know for sure I can request this info from a colleague.