And the concentration of ethanol you plan to use. The stock pumps have no data for higher than stock pressure flow, so I wouldn't recommend running higher than stock pressure. Flow for two stock pumps should be fine for 43.5psid, and Petar got 789RWHP at this level. These ID1000 injectors are supposed to be good for duty cycles above 90%, FYI. However, if engineering the whole fuel system correctly for E85, I would make sure you were using E85 compatible pumps, SS tubing or PTFE hose everywhere.