I would. You don't need much, the stock flathead unit will be fine. If you are running a 97 Stromberg or equivalent, they want 2-2.5 PSI, gravity alone is like .5 PSI. That may be minimalized or restricted further by the size of line. It may run on gravity alone, I guess it depends on what you are running (multiple carbs on a hot flatty), what you expect from it (grocery getter, boulevard blaster or land speed car), etc. Run the Ford pump, it works and doesn't need a regulator.
it did for the stock model A, any flathead with larger than stock fuel requirements, may need a little extra help from a fuel pump. Are you using a stock 4 cylinder flathead or a V 12 flathead or something in between ?
all us americans just figure a f/h v-8! when 'flathead' is stated!--though i imagine the tongue is firmly in...
My avatar had a flathead V8 60 in it with a fuel pump, never tried to run a V8 without a fuel pump. However my 30 pickup had a B motor with an Ansen manifold and a Holley 94 and it worked fine most of the time without a fuel pump. I did discover (the hard way) that you better keep plenty of gas in it, was in the Flint hills in Kansas and on a long grade with about 1/2 tank, it died going up the hill, let it sit for a few minutes and started again and made it up the hill. Gravity feed didn't keep up on the hill so I installed an electric fuel pump and pressure regulator and ran it like that for years with no problems. I wouldn't try a flathead V8 without a fuel pump, on a stock Model A the carb is several inches below the bottom of the gas tank (up draft carb) and with the Holley 94 the fuel inlet is about level with the bottom of the gas tank. In the pictures you can see the stock up draft carb is about 6" below the head and in the second picture the inlet on the carb is even with the distributor. On my V8 A the inlet on the carbs is about even with where the bottom of the gas tank is mounted.
A stock T carb is lower than the fuel tank outlet. They backed uphill because reverse was a lower ratio than low.
Been there and done that. Correct It is lower, but not a lot lower. With 3 full-sized people, I was doing fine from the river road to near the top of a half mile pull ( and less than half tank ) when the gas wouln't flow. I have found some pretty steep hills, that I could pull in high gear solo, full tank. As @jnaki says YRMV