Well, it took a while. But I finally found an 8" piece. It's made by(or at least sold by) the same company that made my hose barb. American Grease Stick Company, part #BLX-608BK. The Balkamp part number is BK 8131246. It's listed as a brake line assembly adapter. Only $3.49 each, plus tax.
https://www.napaonline.com/en/p/BK_8131246
I Googled that AGSC part number & didn't get much of anything. I assume that other part houses sell the same thing. Can't verify.
Anyhow, I prefer the hose barb, But, for those who might prefer the line & nut, there's a link to a cheap source.
And yes, I realize that most nowadays don't wanna use any rubber hose in the fuel system. I'm old school, & on a VERY low budget. So, I'll use some rubber hose & some metal line, as well as inline fuel filters. I'm running ethanol free 93 octane gas. This system worked just fine on all my previous race cars, as well as lots of street cars & trucks. So, maybe it'll get me by for a few more years. I'm guessing that I'm not the only guy still using rubber gas line. But, I know that lots of guys would use only the latest, greatest braided hose & AN fittings.