Dave,
I'm not fully understanding you. Let me ask in two questions:
1) When I switch to brass fittings, can I use the current nylon hose and just swap to brass fitting (i.e. a compression fitting with ferrule and insert) or do I need to replace the nylon hose when I switch to brass? The hose is "Nylon 12" (more specifically Polyamide PA 12-PHL). OR should I switch to "brass barb fitting" with a clamp.
2) Before I get around to switching out the Voss fittings, I was going to just try to get buy the "clip" and reinsert it in the existing plastic fitting. That would buy me more time. I'm concerned about driving around without this clip in place. However someone else said that clip is only used to "remove" the fitting and does nothing to help hold the fitting in place (I'm not sure if that guy is correct about that). I f I keep the Voss fittings for a while longer, I will add a hose clamp over the barbed end as you suggest.
Also, I noticed this Voss fitting is also used at the Fuel Pump inlet fitting in addition to the Racor inlet and outlet (and maybe other places, like a t fuel tank, that I have not seen yet).