If going to the trouble of having a custom tank made...it seems so odd not to design it so it doesnt need an additional swirl tank. Even more so when it's already a small tank which wont suffer badly from surge in the first place.

And given that overall design, just use an EFI pump for the lift pump, or you could use one of the Carter/FM carb type pumps instead.

Those old crappy Facet type pumps flow feck all. That red top would barely be enough fuel to maintain supply for 250-300hp.

Above that level your swirl tank will be draining.