Starting to button up some necessary things on my abody and wondering what everyone recommends for fuel line size. RB 512, AED 1050
Will be a nitrous car but will run a separate fuel line for that

Both my s/strip 340 cuda and the 440 race Cuda had 1/2" lines. Some may say that is overkill and they went quick with 3/8", I say do it the once.

Old stocker trick. Run 1/2" from the pump to the carb. It's like having an extra fuel bowl of fuel. On the carb fittings, remove the filters (assuming you are running a Holley). Then hog out the inside of the fitting.

Nice... I was thinking 1/2 inch anyways

Finelines bent me up a 1/2" line for my Dart Sport and year one has the sending unit. Works great. The 1/2" line in the stock location is a bit of a pain to install but final fit is great.

I agree, go 1/2. You will have enough plus a decent margin.

-8 ordered! Thanks

A lot has to do w/pump design and the bigger pumps need bigger line period. My Magnafuel 300 series pump needs a #10 from the pump to the regulator and bypasses directly back into the cell. Now a Mallory 140 or Holley equivalent can run 1/2 but not the other way around............

Some of the #8 AN flex lines are not .500 I.D.
Sorry to be the bearer of bad news.

If needed, higher pump pressure (like 60) allows use of a significantly smaller line.

And if you call the fuel pump companies and talk to them about their BIG pumps, it's the opposite due to "resistance" and bad back pressure...........

Except for every EFI car (and that means EVERY car) made since the 1980s, which are regulated down to (frequently) 43.5 psi at the rail.

I use 55 PSI so the fuel will atomize better
on EFI.. Chrysler did it for years on muli-point
injection

There is hydraulic engineering math for the output of a fuel line in ID vs. pressure.
Fuel flow varies (roughly) with the square of the inside diameter (actually slightly more due to Poiseville, etc.). 5/16" = .077 In.2, 1/2" = .196 in.2, more than 2-1/2 X as much.
Flow varies with the square root of the new vs. old pressure. Holley "blue" = 14 psi, EFI 55 psi?
55 ÷ 14 = 3.93
3.93^.5 = 1.98
A 55 psi EFI pump flows 198% as much as a Holley blue, which makes a 5/16" line @ 55 psi flow as much as a 7/16" Holley-fed line.

Obviously, regulate it down to what you need at the last moment.

I use a 1/2" sending unit in my stock fuel tank, 1/2" line up to the regulator, and 3/8" line(-6) from the regulator to the fuel bowls.

The regulator is a Holley return style, so I run 1/2" line out the bottom of the regulator, all the way to the stock fuel filler tube.

The Aeromotive pump runs a lot quieter and cooler since switching to this setup.

Regulator is set at 5.5 psi.

I run a stock tank with a 3/8 sending unit and a 3/8 line to the reg and carb. But I only want a 10 second street car which so far its fed my 850 with no problems. But I agree if your looking to go pretty fast just go with 1/2 and be done. I ran my 3/8 line in the stock location so it also fits in the factory clips with a little working. If I went to 1/2 I would not use the stock clips. Ron

I run a 5/16 line up to the Carter street/strip mechanical pump. 3/8 from the pump to the carb (no particular reason). Seems to run 121 mph and past without nosing over.

Has a seperate, dedicated fuel system for the new N20 system. (Oops, did I say that out loud?!)

I redid my fuel line last year. Went with 1/2” all the way from the stock tank through (2) pumps to the carb. Found a stock style pickup with 1/2” tubing on eBay. The fuel pressure became much more consistent, as did the car. I’m sure 1/2” is overkill for my street / strip car, but as long as I was bending line, I figured there was no reason to go smaller.

Ah looking to cheat a little ey ?? LoL Just kidding. We still have the stock 5/16 line on my sons Dart and its still pulling good through the traps running 11.40's @ 117. I keep telling him to change it as we even have 3/8 line for it but its running good for what it is so he has been putting off replacing the line for now. Ron

I dont blame you as now your good to go if you want to go a good bit faster one day. I only went with 3/8 because I wanted to run it in the stock location and clips and I know I dont want to ever put it in the 9's even if I had the money because it will stay a street car as long as I own it and I dont want to do all the updats to run in the 9's for a street car like a full cage as I like just the 6 point bar for driving on the street. And I figure 3/8 should be fine for even lower 10's if I ever decide to do some improvements. But you did the right thing going with 1/2". Ron