Is anyone using this fuel pump? It's rated 120 gph @ 5.5 -7 psi. Will I need a regulator for a Holley Street Avenger 570? Holley recommends 5-7 psi. 

That pump should play well with your carb per Holley's pressure spec, but best to verify what pressure it actually puts out. That will tell you whether you need a regulator or not.

We run a similar Carter for a different 422” engine; Same rating and use a regulator set at 5psi on the recommendation of our carb guy. It has not failed in severe dirt track conditions. We feed the pump with a -8 line and the line to the carb from the pump is also -8. Fittings are drilled larger.
I’m sure this pump would feed a dual quad Holley equipped big inch engine or any engine I could think of. I only concern my use of any pump with not having too much pressure on the needle and seat (regulator) and the volume it can put out.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I've used a Holley Competition pump along with a regulator for years. Works great! Its listed for a 427 FE.

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Are really going to need 120 GPH?  Is this for a race car?
Get the small street version, it will be all you need. I'm running one on a dual 550 carbed 322....plenty!
(You're talking about an electric pump, right?)

"FREE SAMPLE"

Lord... that # is a mechanical pump..

56 Vic, B'Ville 200 MPH Club Member, So Cal.

What "small street version" are you talking about?

I'm a believer in running a full mechanical (diaphragm style) pump on a street engine. The one that specs for a "police" FE 428, four barrel is good for a 335 HP stocker. You just have to be sure you have a big enough suction line to the tank - 3/8 will work. The key issue: you have to have delivery of at least 30 gph at the desired carb pressure to support 300 HP. This number is usually reported in "pounds per hour" on a dyno sheet.
 
This chart came from an old Holley catalog and shows how the flow drops when regulated to the desired carb inlet pressure of 4.5 psi. The term "free flow" implies no back pressure so that isn't the number you want.   

 
 Steve Metzger       Tucson, Arizona

Thank you.

The OEM line from the tank is 5/16". The Carter pump inlet and outlet are 1/4 NPT. It sounds like I'll be fine with the Carter pump and a regulator. I would only use an electric pump as an auxiliary for starting on hot days, after car has been sitting a while.