An Fuel Pump Fitting
Thread Starter
Instructor
Joined: Apr 2004
Posts: 233
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From: greenville sc
An Fuel Pump Fitting
I'm about to order some AN fittings and steel braided hose form Jeg's to make a fuel line from the fuel pump to carb filter. Can anyone tell me what size Npt thread that goes into the fuel pump on a 74 factory Big Block fuel pump? I think its 3/8 but I'd hate to order the wrong fitting. Also is it any trouble to connect the braided hose to the fittings.
Safety Car
Joined: Jul 2001
Posts: 3,921
Likes: 2
From: York PA
Originally Posted by blackbeauty74
Also is it any trouble to connect the braided hose to the fittings.
Last edited by stickboy; Feb 5, 2006 at 04:17 PM.
Racer
Joined: Jun 2005
Posts: 400
Likes: 11
From: Lubbock Texas
Like stickboy says it is an invetred flare - an fitting. But i believe that the inverted flare is 1/2"
I come up with jeg's # 555-100540 they have it in other brands also.
they only list a 1/2" & 5/8". So i am gonna guess that it is the smaller of the two.
I come up with jeg's # 555-100540 they have it in other brands also.
they only list a 1/2" & 5/8". So i am gonna guess that it is the smaller of the two.
Tech Contributor
Joined: Aug 1999
Posts: 14,370
Likes: 6,364
From: At my Bar drinking and wrenching in Lafayette Colorado
The outlet thread size on a stock Chevy fuel pump (big block or small block) is 5/8-18 Inverted Flare. The 5/8-18 inverted flare nut fits a 3/8" steel tube in the stock setup. To adapt, you need an adapter from 5/8-18 Inverted Flare to -6 male AN (if you're going to run 3/8" hose & hardware). If your fuel pump is an aftermarket fuel pump (like a Holley or a Carter), it will have 3/8" pipe threads on the outlet. But this is not the stock pump configuration.
