Would a bigger pump, say Welbro 400 (instead of a 255)cause problems with a lower HP engine? All engine now with carburator(850 Proform DP) but probably FI and power adders later so I will need the bigger pump eventually. System will be -6 pressure and -8 return, metal lines, with Aeromotive regulator in engine bay. Pump will be in fuel tank. Looking at at least 600 HP to start. The 400 would be too much pump until further mods are done. I have been doing some research and some people have reported some problems with idle quality and fuel heat soak. If you are running a bigger in tank pump than needed are you having any problems?