I recently replaced the ford 2100 2 barrel carb on my 292 in my 56 victoria with a holly 4 barrel . The ford tag on the Holly was DOPF 9510 V which was meant for a Ford service replacement on a 1970 289. I believe the CFM is 450. Choke is manual. I would think this size carb would be just about perfect on a stock 292 being that I want originality, smooth idle, and decent gas mileage. By the way I am running the 57 and later 4 barrel manifold and the 292 is a 1961 model with the small valve heads. After the swap, the difference in acceleration was obvious . The car has much more pep now. Problem is, I quickly get an accumulation of black soot on the inside of my chrome exhaust tips and can see traces of black smoke when I rev the engine. Car idles smooth before warm up in drive with foot on brake in traffic but has a bit of intermittent stumble when warmed up. The carb was given to me by my neighbor who was a parts manager at a Ford dealership back in the 60's and 70's. He saved a lot of stuff when they cleaned off the shelves ( That's what he told me) His garage was a treasure trove . Anyway, the carb looked nearly new but had sat in his garage for at least 30 years so I put a new rebuild kit in it. I noticed it had #55 on the jets. I also set the floats dry ( upside down and parallel) . I am hoping someone can advise me on how to eliminate the black smoke  and stumble at idle at at the warmed up operating temp. One old timer told me I'm expecting it to idle like an old flathead and am being too picky. .
George

55 Jets should be pretty close. I have  #56 in mine and #57 in Buddies 390 Holley. My first Question is how did You set up the throttle Plates for initial adjustment? If you turn the Carb over there is a Transition Slot just above the Throttle Plate. The initial Adjustment should just show a "Square" below the Throttle Plate. The more of that Slot that is exposed draws more Fuel .You are not running on the Idle Circuit controlled by the Idle Mixture Screws. You shouldn't need to change that initial setup much.If You need a little more Air open the Secondary Plates a little. Resist the Temptation to turn up the Idle speed Screw. There should be a small Screw in the Base that contacts the Secondary lever as You turn it in. Black soot means it getting too much Gas. Check the Float Level by removing the Plug in the side of the Fuel bowl. (with the Engine Off). You should get just a trickle of Gas when You rock the Front of the Car from side to side. Much more that that means the level is too high and should be adjusted used the adjuster on the Float Bowl. Just a couple of Suggestions from my own Experiences when I changed mine to later Carb and Distributor. Once You get it setup properly it will Idle properly and You should not have any Soot etc.

  

Any time you are using a carburetor tuned for one application on another application, that carb must be tuned for the new application.  It is very likely that it simply needs to be tuned.

If the engine is in good condition, valves adjusted correctly, and the ignition is tuned and functioning properly, try adjusting the idle mixture and smaller jets.


Lawrenceville, GA

Many parts left on shelves and "taken" we're take off parts from warrentee work. Carburetors were at the top of the list. Many were never returned to the manufacturer and could have a defect. I have actually purchased a few in the replacement boxes which said "warrentee. I agree with others about the ignitial adjustment on the secondary plates as that has snuk on me too. Good luck.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I think the Ford # is D0PF-9510-U not V. It is a service replacement for several Applications.

  

I’ll suggest setting the two idle mixture screws with a vacuum gauge or a wide band oxygen sensor.  My own preference is for both screws to be adjusted the same number of turns from their seated position when the final idle screw adjustment is obtained.  Does screwing in the idle mixture screws have a noticeable effect on the idle quality?  Either mixture screw being screwed in should have the engine wanting to ‘die’.  If the engine idle is unaffected by turning the screws in to their seated positions, then as mentioned, the primary side idle transfer slots may have too much exposed and will require some secondary blade adjustment in which to correct.  It could also be a gasket or metering problem within the carb itself.  Ideally, the best idle mixture adjustment should occur with the screws 1-1½ turns out from their seated position.
 
You don’t say if this carb was new or a ‘pull off’.  If it’s a ‘pull off’, then it is suspect for having an internal problem.  Beyond that, there are several things to check for when kitting a Holley carb.  The power valve gasket is at the top of the list and depending upon the style of power valve and its gasket, the gasket may have slipped when tightening the power valve.  It’s a given that the carburetor kit gaskets must be exact replacements and there are several different ones for Holley carbs.  Another item to check is the flatness of main body surface where the metering block gasket must sit.  If over-tightened, then there will be some warpage at the corners which keeps the metering block gasket from being adequately sealed.  That can be repaired but the carburetor must be completely disassembled to do so.  There is a fixed idle circuit on the secondary side of the carburetor and the float level back there is a controlling factor for that.  You can try running the rear float level 1/8” below the sight plug threads and see it that helps.
 
Also make sure the idle bleed holes are all clear.  These are located fore and aft of the venturies and can be seen when looking straight down the throats of the carb.  Any stoppages of those will make for a richer mixture whether it’s the idle mixture or the main feed circuits.  The outer bleeds are for the idle circuits while the inner bleeds are for the main circuits.

Lorena, Texas (South of Waco)

My book lists the DOPF-9510-U carb number as being a service carburetor for the 302, 390, 428, & 429 engines. No particular year models are specified so that part number would cover a wide range of year and cubic inch applications.  It’s obviously not going to be a perfect bolt on and run in most cases.  As such, some tweaks and/or adjustments will be needed to match that carb to the PCV valve, manifold vacuum, cubic inches, transmission, etc. for your particular combination.
 
As far as the adjustment range on the primary idle speed screw versus the inaccessibility of the secondary blade screw adjustment, you are not expected to mess with the secondary blade adjustment on an oem application.  The factory engineers really don’t want you messing with it.  The problem with making the secondary blades with an accessible adjustment screw would require another pair of idle mixture adjustment screws at the rear of the carb for the secondary side of the carburetor.  That would be a problem for the model 4160 Holleys as they do not have a metering block that is accessible at the outside of the carb.  Many of the model 4150/4160 Holley carbs have a fixed amount of idle feed on the secondary side and these do not give much leeway in the throttle blade adjustment.
 
Where the carburetor is being fitted to another application, then some adjustment may be required in that area.  An option to increasing the secondary throttle blade opening is a pair of small holes in the primary throttle blades so that additional air can be put into the engine without exposing too much of the fuel transfer slot.  Before doing any drilling on throttle blades, other options will need to have been eliminated.

Lorena, Texas (South of Waco)

At 30 years old that power valve is probably hard as a rock and not being held completely shut at idle , I'd change that first.

Thanks to all for advice on my carb. I am busy with plumbing issues in the house right now but will try the sight hole float adjustment first when I get the time. I have never used a vacuum gauge but am considering buying one . The Walker kit I used didn't give much instruction on settings other than the dry float settings and choke settings. The carb was a takeoff as I could see that it had slight useage And I agree with Ted that one must wonder why a nearly new carb was replaced. Reminds me of an advertised NOS teapot carb on ebay recently that was run for 30 minutes and then taken off and now for sale decades later.By the way, I googled Holly DOPF 9510 V and found Holly master list that listed both a U and a V model with the V being for 1970 289 cars and the U for 302 and larger. My gut sense tells me not to spend much more on this carb as it might indeed be defective. Once  again, thank you all for the input and I will let you all know the outcome after i try a few tweaks. 

When I was looking for a 390 cfm Holley model 8007-0 ( which is what Holley recommends and is used by several of us on this Site) for my Buddies Car which is what I have on mine and really happy with it, I found a Supplier called "Carbsandmore" based in Texas. They list a rebuilt warrantied 390 CFM for $350.00 which is about half what a new One costs. I did find a good used One locally but I was very tempted to order One from them if I hadn't. I know from experience working on mine and now my Friends 56 doing the Conversion to later Distributor and Carb made a world of difference in the way it runs. If You can't get that Carb straightened out don't give up on it. Just bite the Bullet and buy a good Carb for it. Well worth the Expense. I have been in your situation when I purchased a 465 CFM Holley Carb on Ebay to do this Conversion. Appeared to be unused. Turns out someone swapped the Base for one off a 600 CFM Carb so basically the One I bought is useless and worthless.