1934 Ford flathead fuel push rod

[Cmspencer]

Hey folks I’m working on a 1934 Ford BB truck project with a 21 stud flathead.

I’ve run into some confusion regarding the correct push rod length to use for the mechanical fuel pump. My engine is a 1934 21 stud flathead with what I assume is an original style aluminum intake manifold. Many sources I read through call for the 7.87 inch push rod for an aluminum intake. However when I installed the 7.87” push rod, it appears there is not enough travel for the push rod to actuate the pump lever. I had a spare 8.87” push rod that I tried and it looks like the proper length to actuate the fuel pump.

The rear of my intake manifold measures approx. 2.5” tall. I have included a photos of the intake manifold with the 7.87” and the 8.87” push rod at full lift.

I’m guessing that I need the 8.87” push rod, but that’s a guess. But then why do all the catalogs including the green bible call for a 7.87” push rod? Any help is greatly appreciated! (Newbie here so I apologize if this topic has been covered)

[19Fordy]

Cmspencer: This may help.
https://www.fordbarn.com/forum/showt...l+pump+pushrod

A Fordbarn SEARCH of Fuel Pump Push Rod will reveal more info.

[rockfla]

Delete. was thinking 35 not 34...Sorry

[Kube]

Originally Posted by Cmspencer

Hey folks I’m working on a 1934 Ford BB truck project with a 21 stud flathead.

I’ve run into some confusion regarding the correct push rod length to use for the mechanical fuel pump. My engine is a 1934 21 stud flathead with what I assume is an original style aluminum intake manifold. Many sources I read through call for the 7.87 inch push rod for an aluminum intake. However when I installed the 7.87” push rod, it appears there is not enough travel for the push rod to actuate the pump lever. I had a spare 8.87” push rod that I tried and it looks like the proper length to actuate the fuel pump.

The rear of my intake manifold measures approx. 2.5” tall. I have included a photos of the intake manifold with the 7.87” and the 8.87” push rod at full lift.

I’m guessing that I need the 8.87” push rod, but that’s a guess. But then why do all the catalogs including the green bible call for a 7.87” push rod? Any help is greatly appreciated! (Newbie here so I apologize if this topic has been covered)

It is very possible, even probable, you don't have the correct valve chamber cover, aka intake manifold.
From your photos, it appears you require the longer rod.

[rockfla]

Here is a 34 vs early 35 intake manifold for comparison, the fuel pump stand opening tells all!!!! 34 is diamond shaped. The gasket is covering the opening but based on what I see you have one of the two posted intakes. Based on your third picture It "appears" like the correct intake from what I am "not" seeing in shadows under your gasket.

[mercman from oz]

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A 1934 and early 1935 intake manifolds for comparison - rockfla

[mercman from oz]

Add one of these Spacers to lengthen the Fuel Pump Push Rod.
These are Genuine Ford V8 Spacers.

[Terry,OH]

It was the later 35 aluminum intake that first had the lower profile at the rear for the shorter fuel pump rod, later aluminum intakes continued with the shorter profile. So most aluminum intakes do take the shorter fuel pump rod, except 34 and early 35. The parts catalogs perhaps missed this.