[bestgenman]

One of the things about 213 stratoflex hose (or any self assembled fitting) is the possibility to cut a “flapper”.  When screwing the tailpiece into the threaded part that is screwed onto the outer part of the hose ( I’m lacking the correct name for the second part of the two piece field assembled fitting), you can cut a sliver of the rubber interior into a perfect flap that acts as a check valve.  Admittedly, I haven’t followed every step of your project but if you think there is a problem with fuel flow and it involves a hose you have worked on then you check each piece.  Use your portable 12v pump or manual pump and isolate each piece and try to move fuel through it in the direction of flow.

One other thing I didn’t mention, when changing filters remove only one filter at a time.  Pre fill , install and run engine enough to guarantee flow then shut down, remove the second filter doing the same thing.

Hope you can resolve this issue.
Gordon