The answer to your question is...it depends. Anytime you change something on a system from how it was originally designed you need to redo the math for that component.
There's alot of great ancedontal and experience based feedback in this thread, but always be cautious on the internet from following along with something, because your situation may be different. You may find someone with essentially the same setup as you and you can copy what they did to save time.
Ultimately it comes down to what peak GPH you require, and what pump can do that GPH at the desired pressure.
You have to pay attention cause there's marketing tactics, like saying it flows 35GPH but it's at zero pressure.
So for fuel system math/flow dynamics..
On a N/A motor I had calculated 30gph requirement on one of Selahdoors threads this year, and 70GPH on my truck.
To your other question, I have heard the mechanical ones do 30GPH, and a true 30GPH. They run faster with the RPM and produce force not limited by the bit of electrical power you supply them.
From that, it's no surprise what others have said with turbos in this thread like
@Garbage_Mechan about being able to pull them down to zero.
The guys with the fuel pressure gauges that responded to you is very good examples.
To summarize, you need to find something that truly flows 35GPH ish @5psi to the injection pump if you are stock N/A. The IDIs get fuel hungry quick when you start modding.
If you need any calculation help let us know. We also have great vendors in this community.
I'm going to run a Warlbro high pressure on my turbo build and regulate it down. If you have any plans to start modding and turbos I would look into that..
Also holley blue and black.
Not sure what your plans are for the future.
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