I'd agree with tappet adjuster Eddie that over fueling unlikely caused by fuel pump position but rather issue with float height setting / float needle valve sealing against seats and/ or fuel pump pressure being to high.
Most early carbs are low pressure high volume feed( ie webbers etc 4psi). Its worth checking floats have integrity as well ( not leaking) - test in hot water for leaks.
I work with pumps a lot in the oil and gas industry for lifting fluids out of wells and the key point is that they need primed with liquid ( not air/ gas) to pump efficiently where they can lift liquids to the required location and at the required pump "head"( think pressure), so you could site fore or aft but they would be best sited at least below the mid point of fuel tank depth, or close so they are always primed assuming you keep the tank filled up. The lower the better imho.
FH
Most early carbs are low pressure high volume feed( ie webbers etc 4psi). Its worth checking floats have integrity as well ( not leaking) - test in hot water for leaks.
I work with pumps a lot in the oil and gas industry for lifting fluids out of wells and the key point is that they need primed with liquid ( not air/ gas) to pump efficiently where they can lift liquids to the required location and at the required pump "head"( think pressure), so you could site fore or aft but they would be best sited at least below the mid point of fuel tank depth, or close so they are always primed assuming you keep the tank filled up. The lower the better imho.
FH