Will this carburetor work? What is it?

ags290

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I am preparing to do a head swap on my son's 1964 1/2 Mustang. It is a 170 with a C4 transmission and a Load O Matic distributor. I know this is not the correct carb. It should be an Autolite 1100. This one is some type of single pump Motorcraft. The tag on the carb is : DOFFK A7H25. The original plan was to kit the carb while the head was at the machine shop. Without knowing what the carb is I can't get a kit. The car starts right up and idles OK but the performance is weaker than I think it should be and the mileage is awful. I have pictures of the carb but can't figure out how to upload them. As always any help is appreciated.

Kevin
 
look to see if there are any ford part numbers on the carb, they are generally stamped on the base near one of the bolt openings.
 
When I bought my car it had "DOPF K" on the aluminum tag. I found out it was a Holley Model 1940 carb. It was a 1970 Motorcraft (Ford's replacement or service parts division) replacement carb for the original Autolite 1100. Search "Holley 1940" and see if that's the same carb you have.

I'm assuming your car still has the original Load-O-Matic (LOM) distributor. That distributor requires a matching carb that has a "Spark Control Valve" (SCV) to provide the correct vacuum to the distributor. On both the 1100 and Holley 1940 LOM carbs there is what looks like a Holley power valve screwed into the side of the carb body. That is the SCV. Please note that Motorcraft did make Holley 1940 carbs with AND without the SCV.
 
Thanks for the information. I googled Holley 1940 and that is indeed what I have. It does have the "power valve" type screw in valve on the body of the carburetor so it should be compatible with the LOM distributor correct? Now my question is should the 1940 have 2 accelerator pumps for an automatic like the Autolite 1100 does or is that an 1100 only deal?

Kevin
 
I am pretty sure the 1100 for either manual or auto had only 1 accelerator pump . Some automatic version carbs had a diaphragm to slow the return to idle - perhaps that what you are thinking is an accelerator pump .
 
Yes, if the carb has the SCV (power valve looking thingy) on the exterior then it will be compatible with the LOM PROVDING that the passages are clean and clean and the valve is functioning correctly (diaphragm and spring not broken).

The 1940 has an internal piston for an accelerator pump a al Quadrajet. It's an internal vertical piston inside a bore. You should see a bent rod that goes from the side of the carb with the end inside the middle of 3 slots in a vertical plate. The rod goes into the air horn. The end inside the air horn is what attaches and activates the pump.

If you're familiar with Holleys then there what looks like a 4150-style accelerator pump on the back side of the carb. This is actually vacuum break diaphragm. There should be a bent rod from the diaphragm to the choke rod end. The 1100 didn't use a vacuum break, it relied on a spring and air flow to break open the choke at start-up.

tanx
 
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