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By ejstith - 17 Years Ago
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I am getting ready to put a Holly 4 barrel on my '56 272, bone stock. Has a manual 3 speed and 3:78 gears. Holly recommends a 570 CFM. I was thinking of a 390 or 450. Seems the 450 is for dual 4 barrels and doesn't have a choke. The 390 is more expensive than some. On my 2 barrel now the linkage goes to the right side of the carb and pull back at the bottom of the linkage. Does any 4 barrels work that way and if not other than riggin' something from the right side what's the options? I want a brand new carb out of the box, no messing with it. Plug & play! Thanks ..
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By Larry D - 17 Years Ago
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Hi, Nice looking '56! I think you would be happier with a smaller c.f.m. four-barrel on a stock 272 V8. Holley makes a nice 465 c.f.m. http://www.holley.com/0-1848-1.asp that works great on the mid-fifties Fords. They also show up on ebay both new and used. As for your throttle linkage, I think you would need to change the bellcrank to one from a four-barrel equipped '55 or '56 to get the throttle linkage on the left side. I've never tried mounting a single four barrel backwards, but other than lengthening and rerouting the fuel line and wiring an electric choke, I imagine you might be able to adapt it to work with your current linkage.
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By rgrove - 17 Years Ago
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I just replaced my Edelbrock 500 with a holley 390 last year. Mathematically, teh 390 is plenty of carb for a 292 up to around 5500 rpms or so (and mine has never seen that), IIRC. Mine is a 292 with a slightly bigger cam in a 56 sunliner with a ford-o-matic. 390 offers much better mid-throttle response, and better mileage. It pulls a little less than the edelbrock at WOT. I did have to go up several jet sizes on the holley, though, and im still chasing a bit of a stumble when it kicks into passing gear. Overall, for a driver, Id say the 390 is probably about the right size, but YMMV
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By ejstith - 17 Years Ago
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So why did you change from an Edelbrock to a Holly in the first place? Was it giving you trouble? I am an old Carter fan from the 60's and I know Carters (now Edelbrock). I never did have much luck keeping a Holly going but that could have changed over the years. My son is about to crap with me thinking of putting an Edelbrock on it. He has a Demon (great big) on his Chevy. I'd like a 450 Holly but they don't have a choke. The 465 is expensive as hell. The 390 may be the choice. It will be between it and a 500 Edelbrock. Thanks ..
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By speedpro56 - 17 Years Ago
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I believe you will be A LOT HAPPER with the 390 cfm on a stock 272. If I was a betting man and you had two identical cars with 272s, one with a 390 and the other with 500 cfms and you ran them in the 1/8 and 1/4 strip the 390 will beat on both ends with ease. I have a 272 in a 57 ford bone stock and can tell the 57 holley 400 cfm 4150 is all it can take. I took off the original 2 barrel holley and am not totally convinced it's that much faster with the 400 cfm carb.
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By rgrove - 17 Years Ago
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I replaced the edelbrock with the Holley in an effort to get better mid-range throttle response and better driveability. I got that with the 390. It is much more responsive than the edelbrock, precisely due to the smaller CFM. Edelbrock pulled a "little" harder at WOT, but the Holley is a better fit for the driving I do. I had tried tuning the Edelbrock with different rods, springs, etc, and never got it to be as responsive as the smaller carb....
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By ejstith - 17 Years Ago
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And the other problem I have is, well may not be a problem the way I drive, but I have a 1" spacer where the carb will go. The holes in the spacer are larger than the holes in the manifold. I don't really want to woller the holes in the manifold out. I went to the hardware store to check on hi-temp PVC pipe but none was exact enough. There are several things I could do, like JB Weld a slant at the manifold so it wouldn't be so abrupt, but then again maybe abrupt isn't too bad. May make for better atomization. Wouldn't be much difference that the restrictor plate on a NASCAR car. What do ya think? Back in my hot rod days I'd have just ground the manifold holes bigger, but that was then and this is now ...
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By rgrove - 17 Years Ago
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Is it a '56 manifold or earlier? The one that used the original tea-pot carb? If so, some folks make a nice aluminum adapter to adapt a modern carb to that manifold, and it has chamfered openings for a nice smooth transition. I cant for the life of me remember where I found mine (and have subsequently switched to a Blue Thunder intake), but I have to think that a Summit or Speedway would have them, among others. Hopefully someone will chime in here with more info?
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By Eddie Paskey - 17 Years Ago
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Cosco has the adaptor for the tea pot manifold to a later carb. God Bless
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By GREENBIRD56 - 17 Years Ago
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The others have seen this pic before - its a Moroso 1/2" phenolic spacer that is made to the diameter of the the smaller holes in the OEM Ford 4 barrel manifold. There is also one sold by Speedway. Its relatively easy to lay out the "new" carb throttle hole size on the top and file/grind/sand a taper down to the manifold size below. 
So - how many horsepower do the Nascar motors lose to the restrictor plate? Several hundred as I recall..... This isn't the best solution - but its the best I could get for almost no money and still preserve the original OEM manifold. Stepped bores are not a great idea for an intake system. If you don't care to keep the manifold original - look at a picture of the top of a "Blue Thunder" intake and have a machinist mill yours to match. Take about 1/8 - 3/16 off the deck and open the two bores on each side up to a single wider elongated slot.
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By Ted - 17 Years Ago
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Steve’s method in tapering the holes in the spacer to match both the bore size of the carb and the intake is by far the easiest way to alleviate the hole size difference. In lieu of pulling the late model ‘B’ manifold and making the carb bores larger to match the spacer, I have gone to the trouble of machining the plastic carb spacer bores so I could put a tapered aluminum sleeve in each bore that permits the carb and intake bore sizes to match up to each other. Going this route, I machine a step in the top of the spacer which holds the sleeve in place. If the manifold is already off of the engine, then by all means enlarge the carb bores in the intake manifold to match the bores in the spacer. As far as the carburetor linkage goes, on the standard shift models the bellcrank on the intake manifold can be discarded and the linkage can be ran directly from the lever on the firewall (that originally went to the bellcrank) to the carburetor. 
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By RB - 17 Years Ago
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Do not use the 450 Holley. They are set up for 2x4 application on a tunnel ram. The calibration of the fuel curve is not suited to a street car
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By ejstith - 17 Years Ago
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No I have a 57 up manifold with the bolt pattern for a late model Holley or a Carter(Edelbrock). Some of those spacers are expensive as hell. The one I got from Summit was only like 13 bucks. I ordered a half inch but they sent an inch one. I'll figure something out. I'll take it to Home Depot and maybe find something there to reduce the holes in the spacer. Thanks to y'all ...
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By ejstith - 17 Years Ago
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Ted (5/25/2008)
Steve’s method in tapering the holes in the spacer to match both the bore size of the carb and the intake is by far the easiest way to alleviate the hole size difference. In lieu of pulling the late model ‘B’ manifold and making the carb bores larger to match the spacer, I have gone to the trouble of machining the plastic carb spacer bores so I could put a tapered aluminum sleeve in each bore that permits the carb and intake bore sizes to match up to each other. Going this route, I machine a step in the top of the spacer which holds the sleeve in place. If the manifold is already off of the engine, then by all means enlarge the carb bores in the intake manifold to match the bores in the spacer.
As far as the carburetor linkage goes, on the standard shift models the bellcrank on the intake manifold can be discarded and the linkage can be ran directly from thelever on the firewall (that originally went to the bellcrank) to the carburetor.
I have the 4 barrel linkage for a '56 on it's way. I guess I could rig the one on there to operate from the left side but I'll see what the 4 barrel linkage looks like when it get's here. Thanks.
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By rgrove - 17 Years Ago
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Why are people running spacers, anyways?
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By speedpro56 - 17 Years Ago
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The factory holes in the 57 manifold should fit the 390 cfm holley anyway. The spacers from a 57 ford are already sized to fit and should be more than enough to help keep the fuel from percolating from the heat off the manifold. Any thicker spacers are probably overkill on a stock 272 so the easy route as I see it is keep it small and original looking and enjoy.
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By ejstith - 17 Years Ago
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Yeah, I'd would have liked to have done that but the manifold didn't come with a spacer so I bought that one from Summit. Thanks ...
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