Walbro Fuel Pump Orientation

[Shoebox]

I have a Walbro FRB 13-2 12V fuel pump that I will be using as the fuel pump on my '51 Tudor. I believe the pump is normally mounted vertically, however I'd prefer to mount it horizontally on the frame rail near the tank. I called Walbro tech line, spoke to a woman who said she could address any tech question, so I asked if this pump could be mounted horizontally? After a rather long pause she said "should be OK". I really need more confirmation before I mount, plumb and wire based on "should". Pics are attached and I'd like to hear from those more fluid savy than I. Thanks.