Auxiliary Fuel Box Clearance concerns?

[Goin 4 Broke]

In am thinking about adding in an auxiliary fuel/tool box to the bed of my 2015 F350. I have the short (6.75') bed. Anyone installed any of these units and are there any clearance issues with the hitch? How about with tonneau covers, like the Bak Flip? The unit I have my eye on is the 51 gal part number 72746 from RDS. It is 20" high.

Thanks!

[WeBeFulltime]

I received my DeeZee 38 gallon from Amazon yesterday and hope to install it tomorrow. It is 19 inches tall and I am impressed with the build/weld quality. I don't expect any clearance issues, but I don't have a cover.

[Devildog]

I have a 45 gallon from northern tool that has the angled corners on the bottom. Fits in front of the wheel wells real good, and plenty of clearance in front of hitch. Ran it as gravity feed.
No troubles at all. Fill the aux tank up in the morning and drive all day on just the aux with the main tank still full.