Mechanical Fuel Pump & High Wing Aircraft

We also need to take into account the amount of fuel in the tanks.  Full tanks, more pressure at the carb.  Low fuel, lower pressure at the carb.  So, “maybe.” 

The fuel pump has to push past the needle seats in the carb body.  If the drop from your fuel system can't make 2.5 to 3 psi it will not spool up to full power.  The amount of resistance, length of lines and other things start to be important.  Better to have a boost pump than rely on speculation when you really need it.