Also try Napa auto parts and use the Napa brand shocks. I think post #3 by Als48 is correct. I used the shocks from the early 70's C-10 pickup on a '46 Ford coupe.
I'd look a little more. The C10 shocks may fit, but they are for a vehicle that weighs at least 50% more than a '47 Ford. If you like a stiff ride, they may be OK, but there may be better choices.