What is the best psi for a carb setup? I already have a low pressure pump but I read that it still might be to high.
Brian

3.5 psi for carbs

Depends on Carbs, I use a Holly at 2 psi for 10 mm ID line and dual Dellorto 40's
Click to view attachment

I have been using this for my 44idf Webers for about 15 years without a regulator. http://www.cbperformance.com/product-p/3193.htm

I have dual dell's and the cb performance fuel pump. I will see how well it works. If I need to lower to 2psi what regulator would be recommended?
Brian

One thing to keep in mind: If you are using pump gas with ethanol, it will likely kill the diaphragm in the cheap pressure regulators in just a year or two. Then the pressure no longer "regulates".

I plan on 91 octane with no ethanol.

Just down the road from a drag strip.

I don't even know where to buy gas without ethanol except the local airport.
Must be nice....

That's odd,I have the same regulator (12-804) and can't get 2psi its not in the range if the adjustment,anyway 2psi is low,I run 3.2psi and have no issues.
I see in the pic your regulator is screwed right out ,not sure how you get 2psi....just asking .

I know this thread is old, but I want to answer this. the 12-804 has a range of 1-4 psi @ the spec sheet ( https://www.summitracing.com/parts/hly-12-8...a/instructions), and I run a 1-7 psi pump. I run at 2.5 psi now and at 4000-8000 feet altitude. At sea level aggressive driving will starve the car so I turn up psi then.
Now to explain my hiatus, I was amazed that I did not reply until I saw the date of your post. That day was Friday and I just won a 2.0 liter engine on e-bay for $0.99, and this seller says " bring a trailer and you can have the car, my landlord wants it gone" So on Monday morning March 6th 2017 (3 days later than your post) I head out at 4 am to Paso Robles Ca, with trailer. I load the car by 9 am and suddenly get severe stomach pains. 911 is called, I take an ambulance ride, poked prodded and suffer for 20 hrs... then 7 days later; I wake up strapped to a hospital bed, high on morphine and 25 pounds lighter (due to the 20 feet of small intestine they removed). I Had a abdominal stroke. Since I've been fighting to survive, but starting to work on that very same car that cost me my guts. I don't know that anyone will ever read this update, but that experience was life changing and I kinda believe in karma now so...

Oh here's that car "Tang" on the rotisserie. There has been no movement in that garage from that day 2017 until this year 2019 around July..Click to view attachment