I’m sorry, air horn on the carburetor? I’m not Following that

 

Where the choke is.

https://www.holley.com/blog/post/hol...unter_s_guide/

 

 

https://www.holley.com/products/fuel.../rebuild_kits/

https://www.ebay.com/p/1311258336

https://allcarbs.com/product/600-cfm...v=920f83e594a1

What's wrong with your carb? Have you tried a rebuild kit?

 

I’ve done a rebuild kit , it’s running very very rich , I’ve tried tuning but no change

 

What would a Holley 80457 model 4160 600 CFM in eldelbrock numbers

 

Jets? Power valves? Float level? Idle circuits? Choke?

Figure out what pattern your carb is and buy a 500 to 600 CFM Edlebrock.

If you want to simplify things you could get a 4bbl to 2bbl adapter and put an Autolite 2100 2bbl on there. Find one with the at least the 1.14 on the side of the carb. Other sizes listed here:
https://www.ford-trucks.com/forums/1...eral-info.html

The number is in the clock-like circle on the side of the carb:

https://www.vintage-mustang.com/thre...151088&slide=1

Passenger car 390s came with 2bbl carbs in the 1.23 size, so it will flow enough to run most duties very well.

 

Upon reflection: You probably have a governed carb setup. There are some pics here in the links in post 9 of what to look for. Basically it's another set of butterflies under the carb controlled by vacuum via the distributor:

https://www.ford-trucks.com/forums/8...-1-2020-a.html

 

Here’s some pics of it

 

It runs this way?

You have vacuum (maybe) ports open, it appears the rear bowl is missing the plug.

Interesting spring type governor. About which I know nothing BTW.

Nice assortment of plumbing parts.

I would start here so you can get some illustrations of the various parts, items and assemblies:

https://www.hipoparts.com/1964-72-fo...ts-catalog-cd/

 

It does run just not well. The plug was installed after that pic. The plumbing is where it’s a fire truck I’m assuming, it all goes back to the water tank. Would it have to be a specific cab to replace this one?

 

Carb you mean? You are going to have to sort out the governor and the other plumbing related to the carb. The water plumbing is in the way of the fuel line going into the carb. This results in a rubber hose bent in an awkward and vulnerable half circle.

Are you going to keep it a fire truck or are you removing the fire equipment?

 

Yes carb. Yes it will remain a fire truck , the other pluming is not carb related just lines off the carb to the distributor. The plumbing that you see is to keep the pump from over heating

 

Lines between the carb and distributor are for the governor. See post 23.

I would try to clean that whole thing up, easier said than done.

For a carb, the short version is to find a reman of the same thing you have.

 

I’ll try to clean it up, not sure how that will go lol. That’s prob the best ideal just go with that one. I guess it worked for them