I made 175 on the stock air flow meter and injectors with out a FPR but with a walbro and it was 12:1 up high in the rev range. I never measured duty cycle. it would have been dead near 100%. That was with an ECU remap.
I also made a shade under 200 with stock injectors, AFM but with bigger fuel pump and FPR
messy fueling tho:)