Won't run past 3500 rpm

[ford38v8]

THat's a beautiful engine, I bet you spend lots of time admiring that honey!
Your description of what you've tried sounds like you have a fuel issue, and from the picture, I see several possible causes:

Your high vacuum together with the small air filters suggest an air restriction. Try a temporary removal of the air filters for effect.

It takes only a very small air leak to lower your bowl level to the point of lack of fuel on acceleration. The fuel pump's glass bowl should have a cork gasket soaked in oil before careful installation. Also, check the tightness of those worm gear clamps.

The inline filter is redundant with the glass bowl, and may be clogged anyway.

Your rubber flex line may be collapsed internally. I would change out that line to a Shewman fuel resistant line, advertised in the V8 Times, without check valve.

What is not shown in the picture is your tank to firewall fuel line. Original lines being copper coated steel, they rust, flake debris, and develop pinhole leaks. Not cheap, but a Cupronickle fuel line is a great solution to many issues.

[john in illinois]

In my opinion .043 jets are too small . I have a flathead 2 carb engine in my roadster. I put an A/F gauge on it and found stock .045 to.046 worked best.
also it is impotant to check float level very carefully. that has a lot rot do with fuel mixture.
Another variable is air filters. restrictive filters can make jetting difficult.

John

[ford38v8]

Originally Posted by john in illinois

In my opinion .043 jets are too small . I have a flathead 2 carb engine in my roadster. I put an A/F gauge on it and found stock .045 to.046 worked best.
also it is impotant to check float level very carefully. that has a lot rot do with fuel mixture.
Another variable is air filters. restrictive filters can make jetting difficult.

John

John, I missed that. Good call on the jets.

[Tim Ayers]

Originally Posted by john in illinois

In my opinion .043 jets are too small . I have a flathead 2 carb engine in my roadster. I put an A/F gauge on it and found stock .045 to.046 worked best.
also it is impotant to check float level very carefully. that has a lot rot do with fuel mixture.
Another variable is air filters. restrictive filters can make jetting difficult.

John

John,

I agree on both your floats and jets comments. OP- Have you checked the plugs to see if you can tell if it is leaned out?

My 292 c.i. engine with an Edelbrock Slingshot with two 97's. I had to mess with the jetting and I settled back on .046 jets and it runs strong. I tried as big as .048 and as small as .043. With .046's it runs the best.

OP- take the air filters off and see if it changes anything. If that improves it, I'd swap the Mallory back it as well.

[A bones]

Originally Posted by ford38v8

THat's a beautiful engine, I bet you spend lots of time admiring that honey!
Your description of what you've tried sounds like you have a fuel issue, and from the picture, I see several possible causes:

Your high vacuum together with the small air filters suggest an air restriction. Try a temporary removal of the air filters for effect.

It takes only a very small air leak to lower your bowl level to the point of lack of fuel on acceleration. The fuel pump's glass bowl should have a cork gasket soaked in oil before careful installation. Also, check the tightness of those worm gear clamps.

The inline filter is redundant with the glass bowl, and may be clogged anyway.

Your rubber flex line may be collapsed internally. I would change out that line to a Shewman fuel resistant line, advertised in the V8 Times, without check valve.

What is not shown in the picture is your tank to firewall fuel line. Original lines being copper coated steel, they rust, flake debris, and develop pinhole leaks. Not cheap, but a Cupronickle fuel line is a great solution to many issues.

Gold right here