Setting up fuel (& vapor) system from scratch

[Sparky]

Hi,
I'm rebuilding my whole system from scratch and trying to make it as simple and fail-proof as possible.

In the boot I've got a new AR fuel-injected style gas tank (selected for it's larger diameter fuel fuel pickup. At the other end of the car I've got a pair of 40mm IDF carbs.

My plan is to plumb the system as a return-less setup, so:
fuel-tank -> fuel-filter -> fuel-pump (6-8psi, 25-35gph) -> fuel-line to engine-bay (1/2"?) -> FPR (2.5psi) -> fuel-gauge -> inlet to first carb -> pass-thru to 2nd carb

Any suggestions/recommendations on particular products, extra filters? I was thinking of having just a single filter before the FPR to make it easier for the pump to prime, with a new tank I shouldn't be fouling up the pump with rust or such.

My plan is to use modern ethanol resistant fuel line from the pump to the engine, but I know some people may have opinions on using hard-lines? and running inside the car vs under?

Experience with crash relays?

Thoughts on venting the tank? I am having some trouble finding a fuel-rated block-off nipple for the return line port on the gas tank as well as new hose clamps for the large fuel-tank filler hose.

Not entirely related, but with the IDF carbs there really isn't an airbox to plump the crank-case breather to, so I've got an oil catch-can for those vapors.

[Sparky]

Found a reputable regulator from Holley (12-804) and then talked to their tech support for some more details. They recommended they fuel pump needs to be in the 7-8psi range with 6-14psi being ok. In order for the regulator to actually work, the pump needs to have enough pressure to drive fuel into it, so one of those really low pressure pumps isn't going to cut it.
Here's their recommended layout.


For the fuel pump I found a K&N unit (K&N 81-0402) that seems to get good reviews, has a decent price, and the right flow & pressure.

For the fuel-gauge I did a bunch of hunting around to find one that was liquid filled and had decent resolution at the lower pressures. Most of them compress the first 3-5psi. I'll probably go with the Speedway liquid filled model (Part # 91011852), but there's also a nice unit from Autometer (2175).

For the fuel-line, it sounds like 1/2" is way over sized, so I was looking at going to 5/16"(8mm), same as the fuel pump. eg. This ethanol rated stuff from Amazon.

I'm still scratching my head about how to setup the tank venting and some of the other little details...