I have a RDS 60 gal in the bed. Truxedo cover hides everything when not towing. Have the manual valve provided by RDS in the side/bottom of the tank. Have the RDS part in the OEM tank fill neck. Do not have any extra filters. No issues. When parked I shut the tank valve, when driving the valve is open. I did not do the tool box combo, did not think the truxedo cover would work and the tool box is only 6" deep, my truck is too tall to reach into it. I use a plastic foot locker that I got @ Acadamy Sports, same height as the tank and I can lift it out of the truck if I need to. Will sit in-front of the hitch and has the normal tool box stuff in it.
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2012 Ram Laramie 3500 DRW 4x4 3.73 Tow Max Pkg B&W Companion 60 gal RDS aux fuel tank. 2014 Montana 3150RL, 2 A/C's, Leather, 6 Point Jacks, Splendede WD2100XC, Mor/ryde X-Factor, Duravis 250 tires with TST 507RV monitors. 2 x Honda EU2000's