I used the Aeromotive Phantom pump which is only 200 lph. 200 lph is 53 gph or 318 lbs/hour which is enough fuel for more than 600 hp.

The important thing is the flow rating at 60 psi. For a 600 hp engine you need 50 gallons per hour at 60 psi.

I'll have to see how the pump does on the chassis dyno. On the street it holds pressure just fine even at WOT on the freeway. The 400 lph pump would also work in my car but would be overkill.

If the 255 pump will put out 255 lph at 60 psi then it is good for 800 hp. I wouldn't have any problem using one of those in a hot street car.