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abdabbs 12-11-2004 10:51 AM

carburetor delima....
I am going to pick up my new 429 big block for my bus today! Yeah! The delima I am having is that it has a holley pattern 4 bbl intake manifold on it and I dont know much about carbs. What are my options other than needing to get one with the manual choke on it. While looking around I see different air volumes and such.

Any help herewould be greatly appreciated.

TonyC in IOWA
aka abdabbs

Jarlaxle 12-11-2004 12:32 PM

AN electric-choke Holley 1850 (600cfm 4bbl) would work nicely on your 429. However, if you can find the right intake, a Quadrajet would probably be better.

J.B. 12-11-2004 11:07 PM

Carb Problem
Why not get a Carburetor adapter for any carb that you want to put on the intake manifold? :?: : Then you don't have to change the intake manifold. I am sure that you will not have a hood clearance problem. My personal experience is that the bigger CFM carb is always better that a smaller carb. You have 429 CI and you need to let it breathe (dual exhaust). If you are worried about gas mileage(gas is the cheapest thing we buy) than keep your foot out of it. You will appreciate any additional HP and torque you can get. Its nice to have the extra power when you need it, you just don't need to use it all of the time (unless you really want too :twisted: ).


Jarlaxle 12-12-2004 01:00 PM


My personal experience is that the bigger CFM carb is always better that a smaller carb.
Not in this case. My bus's 460 runs a 450cfm Holley Economaster. The key here is the RPM--I doubt his or my engine will ever top 4000RPM (mine is governed at 3800). A smaller carb gives better reponse, torque, & mileage.

J.B. 12-12-2004 08:18 PM

Well, it is a good thing we live in the good old USA :D . We are allowed to have different opinions. It is my opinion that an engine has to breath. What goes in(carb end) must come out(exhaust end). The least restrictions the better. What a shame the venerable and quite power full 429 CI Ford is so severly restricted in this case. We all get to do this thing we do(whatever that is) our own way. The little 450cfm carb may work for you but I still stand by my own experience and opinion that the bigger carb will do a better job providing a better potential for power and torque. Of course we did not even get into the cam thing. We are not talking about hauling around a 3500 lb car. I guess the initiator of this thread will have to make a decision at some point :?: .

Thanks, J.B.

Jarlaxle 12-13-2004 05:51 PM

Then, by that logic, you should run 2 1050cfm Mighty Demon or Dominator carbs. In reality, this would make the vehicle essentially undriveable.

More than once, I've picked up power with a SMALLER carb. Most memorably, replacing an 800cfm carb with a 625 on a Mopar 318 (in a 1969 Dodge Dart) was worth almost half a second, because the car launched MUCH better (more torque), and the smaller carb was ample for a 318 at 6000RPM. I've seen Ford 289's Hi-Po's perk up considerably when replacing the big Holley with a smaller (~600-650) carb.

At 100% volumetric efficiency (which I'm nowhere near, with low compression, small-valve heads, & iron exhaust manifolds), my engine (a 460, not a 429) spinning 3800RPM requires about 500cfm.

J.B. 12-13-2004 08:51 PM

Carb Problems
I would guess that you don't think much of me :roll: . placing words in my mouth to suggest that I would place two overly large carbs on a bus engine(or any engine). As for the rest of the post start comparing apples to apples, not 318 Mopars with 600 cfm carburetors that weigh 3500 lbs to buses that have 429s and weigh 20,000 lbs. Like I said the initiator of this thread will have a choice to make. When I volunteer to make posts on this thread it is with a little dignity. The goal is not to say who is right or who is wrong but to offer an opinion and give the participants in this thread some food for thought. There is more than one way do do the thing we do. I just happen to disagree with your opinion based on my experience. Any way this is my last post on this subject as I wanted to clarify my position, Not beat a dead horse.

Later, J.B.

Jarlaxle 12-13-2004 09:36 PM


My personal experience is that the bigger CFM carb is always better that a smaller carb.
I did not place words in your mouth. I merely illustrated why your words were incorrect.

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