Not personal experience, but judging from Aeromotive's chart of pump performance, the most duty cycle you will be able to run 83# injectors without fuel pressure dropping (at 70 psi total) will be about 82%, or roughly 68 gph total, or approx. 680 fwhp. This is assuming 25 psi boost and no volt booster and gasoline. Add to that number whatever your dual alky nozzles are providing.
But that is not to say you can't run more dc%. You can, and fuel flow will increase (to about 75 gph or 750 fwhp), the pressure will drop (to about 60 psi), but the additional fuel increase won't be linear (or 1:1).
If you wanted to re-tune and ensure linear (1:1) fuel delivery from 0 to 100% dc, you can drop base fuel pressure to 35 psi. This will put toal max fp at 60 psi. The pump and injectors will both do the 75 gph (750 hp) numbers and be linear. You will have to re-tune part throttle and low-speed fueling as it will be a bit leaner (12%) due to the lower base.
