What Carb to Run on my 408 Stroker Duster.

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At the moment I have a Holley 850 QFT race carb on my 408 Stroker engine. I bought my 74 Duster back with the Original 360. Buddy of mine had swapped in this Stroker setup with Eagle kit. Would like to make a bit more streetable and tone the carb down. Any suggestions on that? Thanks.
Is there something wrong with running what you have? I believe my 408, which has an 850 DP Holley, would like a bit more (950?). I'm just too cheap to go buy one!
 
I do have the original factory spread bore intake and thermoquad. I did think of trying that and would be an easy swap.I like the hot air choke deal too. This electric choke I have on it now is worthless.
Find an 800 CFM spreadbore carb, and you’re good to go.
 
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My bad. It's the sbf that doesn't have a spreadbore intake manifold. They say that the edelbrock 2181 is but I looked it up and it's not. Sorry everyone. I screwed up. Goodnight
 
I would keep the original spread bore you have. A massaged one can support mid 10’s and you aren’t counting ounces.
I do have the original factory spread bore intake and thermoquad. I did think of trying that and would be an easy swap.I like the hot air choke deal too. This electric choke I have on it now is worthless.
 
My bad. It's the sbf that doesn't have a spreadbore intake manifold. They say that the edelbrock 2181 is but I looked it up and it's not. Sorry everyone. I screwed up. Goodnight
well that 2181 is for a 351w and although it looks to be for a squarebore carb the openings are obviously wide enough for spreadbore carbs too as the info' states carbs recommended are edelbrock avs2 or performer 600/650. all three are spreadbore carbs and i can't see edelbrock recommending their own carbs that won't fit their own intake. so unfortunately you're wrong again buddy :BangHead: :rofl:
 
I’m not sure everyone here understands what a “spread bore” carb is.

It’s not just carbs that have different sized throttle bores.

The first clue is…….if it will bolt to a square bore manifold, and not have the throttle blades contact the manifold…….it’s not a spread bore.
 
Is there something wrong with running what you have? I believe my 408, which has an 850 DP Holley, would like a bit more (950?). I'm just too cheap to go buy one!
Maybe not. Doing some research I see this QFT carb mechanical secondaries where setup with the 1 to 1 linkage rod. I put a 60% on it. I like that much better. At 1 to 1, the carb was a fuel hound. I think I’m going to try the 40% rod also.
 
Maybe not. Doing some research I see this QFT carb mechanical secondaries where setup with the 1 to 1 linkage rod. I put a 60% on it. I like that much better. At 1 to 1, the carb was a fuel hound. I think I’m going to try the 40% rod also.

when i was like 18 i made a carb 1:1 and it wasn't great... just made it horrible to drive.
 
when i was like 18 i made a carb 1:1 and it wasn't great... just made it horrible to drive.
If all you were going to do was run it on the strip I guess it would be ok, but I'll just swap out the secondary linkage during those times.
 
Get a good tune up in it, take a normal drive for you and read the plugs. Then adjust the jetting if needed and take another drive. Make sure you have the correct heat range plugs in it, the initial and total timing is correct, and so on. I wouldn't use a 1 to 1 setup in it for the street because it won't have good street manners. Experimenting the accelerator cams will help if you want to go that route.
 
With today’s fuel I wouldn’t even consider a carburetor. HOLLEY SNIPER EFI would be my suggestion. Sure it would be a lot more work but the pay off is amazing. Get in turn the key and drive away. No more pumping the gas pedal and worrying if the fuel you just bought will start to stumble the engine from questionable ethanol content and water contamination
 

With today’s fuel I wouldn’t even consider a carburetor. HOLLEY SNIPER EFI would be my suggestion. Sure it would be a lot more work but the pay off is amazing. Get in turn the key and drive away. No more pumping the gas pedal and worrying if the fuel you just bought will start to stumble the engine from questionable ethanol content and water contamination

you must have some pretty bad gas... with a carb and electric choke (will always run a choke) pump once to set the choke and it fires right up, no issues at all.
 
you must have some pretty bad gas... with a carb and electric choke (will always run a choke) pump once to set the choke and it fires right up, no issues at all.

Just making a suggestion is all. The sniper system I have found to be pretty solid. Even with perfect gas I find it to be far superior than any carb I’ve ever had especially on a street car, although a thermoquad is pretty awesome as well
 
Just making a suggestion is all. The sniper system I have found to be pretty solid. Even with perfect gas I find it to be far superior than any carb I’ve ever had especially on a street car, although a thermoquad is pretty awesome as well
I am considering going back to the original Thermoquad and intake. I'm old fashion and also prefer the heat stove choke.
 
Is there something wrong with running what you have? I believe my 408, which has an 850 DP Holley, would like a bit more (950?). I'm just too cheap to go buy one!
I have always found a 950 HP type carb to be better on a smallblock anything.
I finally bought an 850 several years ago for my current combo( because it was black and red)
.dumb.. and sold it and bought a 950. Car is much happier with the 950. I suspect the smaller Venturi size of the 950 makes it crisper on a smallblock. But I am not a carb guru. They have always worked extremely well
 
I have always found a 950 HP type carb to be better on a smallblock anything.
I finally bought an 850 several years ago for my current combo( because it was black and red)
.dumb.. and sold it and bought a 950. Car is much happier with the 950. I suspect the smaller Venturi size of the 950 makes it crisper on a smallblock. But I am not a carb guru. They have always worked extremely well

I have been trying to decide on a carb and read the opposite, that the bigger you go the less booster signal you get (on a smaller engine) so less efficient/power?
 
I have always found a 950 HP type carb to be better on a smallblock anything.
I finally bought an 850 several years ago for my current combo( because it was black and red)
.dumb.. and sold it and bought a 950. Car is much happier with the 950. I suspect the smaller Venturi size of the 950 makes it crisper on a smallblock. But I am not a carb guru. They have always worked extremely well
Even with this old Diamondback Racing (Holley DP) 850 carb and a Super Victor intake, the throttle is extremely crisp and responsive (after much shooter and pump cam work). Most would say it could not be with that intake but it really is very, very snappy. I just think on the big end, a 950 might be a tad faster. Only a feeling but likely won't find out cause as my wife says "It's bracket racing. What's it matter if it's a bit faster?" And at the cost of these carbs, she's right!

I missed the part that the OP has a racing carb with a 1:1 linkage so that be a bit "not so good" on the street. I've not measured mine but it definitely is not 1:1. I need to leave my car alone as it does fine at the track and is just as happy on the street. But we all know how hard that is...
 
I have been trying to decide on a carb and read the opposite, that the bigger you go the less booster signal you get (on a smaller engine) so less efficient/power?
The 950 will have more signal than an 850. It’s why I have run them on all my street strip cars
 
I have been trying to decide on a carb and read the opposite, that the bigger you go the less booster signal you get (on a smaller engine) so less efficient/power?

Those very sharp guys that built the 477 horse 318 of yore( the one I bought and ran a few years back, had a carb guru as part of that build.
He put a hp 950 on it.
I kept it when I sold the car, and ran it on two other cars with lots of success
But that 318 drove like a Cadillac street and strip with that 950.
It’s just my experience and opinion about the 950. Nothing more
 
I have been trying to decide on a carb and read the opposite, that the bigger you go the less booster signal you get (on a smaller engine) so less efficient/power?

Buy good annular boosters. You won’t have a signal issue.
 
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