340 Dart - Fuel Filter location

The filter did once lay horizontally on top of the intake just before the carburetor. When they changed to the unleaded lower octane fuel (1973 I think), the filter moved to vertical down low, right after the pump. Less fuel percolation. If you go this route you'll need the later model pump due to its outlet changing position and the later fuel lines also.
This change eliminated the fuel delivery issues of my 67 273.
I highly recommend following some OEM engineers' examples (pre 1980).