most mods done to the CP3 that increase the flow will require the tables in the ECM that control the pressure regulator be adjusted so it will run right. you will end up with higher then normal fuel pressure and the ECM wont know how to bring it back down.

with EFI Live it is an easy adjustment. you will also be able to trouble shoot many a things with it too. may want to look into getting this before swapping out the CP3. then again your current CP3 may have been a modded pump and the tables may have already been adjusted some. with this truck having a LP and not knowing everything done to it who knows.