Dual Feed Fuel Line Setup

Not on the new ones it doesn't. Have you seen the newer generation from Holley? They are the thinnest, crappiest cheapest things you've ever seen. I had to be super careful with mine when I was installing it that I didn't bend or break it. I remember the old ones were thick as could be and you could barely bend them. These new ones, it's hard not to bend them. They are also crappily soldered together. Just junk. And what makes it worse, I HATE braided line and refuse to use that crappy lookin stuff.
I'll take your word for that and avoid them.
Last one I bought was a Mr Gasket. It was typical steel fuel line with chrome plating but nothing to write home about.
The flares weren't finished well and of course it was made you know where.

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Comapre that to this used late 80s Holley non-chromed.
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My suggestion for the OP was not to have a any soft line between the two bowls. Not braided, not anything. Less chance of leaks.