Where to find new pump to carb fuel line set for '65 Barracuda Formula S 4 bbl

if you're adamant about not wanted to fab 'em up yourself, you could probably make do by using two separate "kits".

the 273 2bbl one as mentioned being the same up to the manifold-- which you've already got and cain't return, so lemonade there. then just scoop up a 4bbl set up and use the carb side to complete the square.

i don't know what carb you're running but eddy sells a hard line with banjo fitting that'll get you most of the way to where the pump line would be.

https://www.summitracing.com/parts/edl-8126
it's not super correct, but it solves a bunch of problems. they also have a version that incorporates a filter if that floats your goat.

or something like this in addition to the line you already have

https://www.summitracing.com/parts/rsd-wpc5701