Nate its not just about the pump rating - the flow and pressure is determined by the metering unit, PCV, drive ratio etc
Before you change anything I would ask your tuner if they are able to map the changed in.
From what I've seen alot of tuners are unable to tune them so the cars runs worse.
It was an r70 cp1 for a R80 cp1H .. I just changed the electronic component over and had no issues
Obvs if I go cp3 on the capa from a cp1H this is more of a head ache I have checked the they are both 2 pin but looking into them they have an internal return line ontop of the normal fuel returns you would find . I may have to blank this possibly ? What do you think