Larry---we've plumbed alot of inverted tanks for guys. At the tank we use a long drop 90* hose end that routes through the tank nose bracket and crimps to a teflon hose. At the side skin, we 'either' is a 90* bulkhead fitting to connect the valve lines or make a longer hose to connect to the valve with a grommet at the side skin. A bunch of them out there, no issues we've heard of.
Tom Swearengen, TS Flightlines LLC, AS Flightlines
Joint Venture with Aircraft Specialty
Teflon Hose Assemblies for Experimentals
Proud Vendor for RV1, Donator to VAF
RV7 Tail Kit Completed, Fuse started-Pay as I go Plan