73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Trailnut on February 10, 2014, 05:45:33 pm
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I have a '73 with 350 engine & 350 trans.
My Dad bought it new in late '72 8)
Had the engine rebuilt last Summer but now i need a new carb - this is just for street / farm use, not a hot rod :( What would be a good carb replacement please?
Thanks
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IMO, I would go with a stock replacement carb as everything will hook up easily using existing hardware.
Also, what's wrong with the carb? They are fairly easy to rebuild. Have you the time and basic skills and tools for such an undertaking? There are members here that can guide you through the process if you are willing.
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Rebuild the stock Qjet carb. It's the best choice, and will give you the best mileage.
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If you chicken out of rebuilding it like I did, you MUST go online and buy a rebuilt one from this website! I just bought one for my 84 Silverado and it bolted right on and fired right up. The truck runs perfectly and I didn't even have to adjust the carb at all. They also come with various warranties available depending on how much you want to spend. I think the 4 barrel one for your truck is this one. http://www.nationalcarburetors.com/lookup.aspx?partnum=nd4503
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If you aren't sure about exactly which one to buy on that website, then just click the tabs on the left, choose Chevrolet Truck, then pick your engine size and year and whether you want 2 or 4 barrel. It's super easy...
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IMO, I would go with a stock replacement carb as everything will hook up easily using existing hardware.
Also, what's wrong with the carb? They are fairly easy to rebuild. Have you the time and basic skills and tools for such an undertaking? There are members here that can guide you through the process if you are willing.
Rebuild the stock Qjet carb. It's the best choice, and will give you the best mileage.
If you chicken out of rebuilding it like I did, you MUST go online and buy a rebuilt one from this website! I just bought one for my 84 Silverado and it bolted right on and fired right up. The truck runs perfectly and I didn't even have to adjust the carb at all. They also come with various warranties available depending on how much you want to spend. I think the 4 barrel one for your truck is this one. http://www.nationalcarburetors.com/lookup.aspx?partnum=nd4503
(http://www.naioa.com/v2/modules/Forums/images/smiles/beatdeadhorse5.gif)
Do it, rebuild it. then you can say yeah i rebuilt it i didnt buy it
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Thank y'all for the advice but i keep hearing about how bad the Quad Jets are so i thought i'd just get a new one and start fresh. Summit Racing has several in their catalog???
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There is absolutely nothing wrong with a quadrajet. Most people who are against them are Strip only drag racers...
You can get a rebuild kit locally also..
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heres a thing also a mild 350 is recommended for only 600 cfms. the quad can handle 800 cfms so your putting money where it doesnt need to go. imo the only step up from a quad is a Fuel injection system thats worth putting money into. not saying much since i run a holly but ive had the same motor/carb for years now only rebuilt it a couple times from getting junk into it from mudding. dont get me wrong the holly looks better than the quad but if i knew then what i knew now i would of rebuilt one (quad) from day one
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Talking about the Qjet a minute. You carb guys forgive me for repeating what you know already: this is for the OP.
Most quads are square. That is, all four bores are the same size. Most of the time you run around with the front bores partially open.
The Qjet is not square. It is a "spread-bore" carburetor. The two primary barrels are much smaller than the secondaries. Most of the time you still run around with the front bores partially open, but more open than with a square bore. That is, for the same cfm through the carburetor, you need to open the front bores more, because the front bores of the Qjet have less cfm capacity than the front bores of a square carb of the same total cfm.
Why does this matter? A carburetor is an approximation to the actual mixture you need. TBI is exact, because it is a closed-loop system where the computer is monitoring the exhaust and modifying the mixture in real time to make it exactly correct. A carburetor is an open-loop system that approximates the correct mixture. Since a too-lean mixture makes the fire go out, the errors in the approximation are almost always to the rich side.
The approximation also works better when the bores are running at or near their design flow. The Qjet in normal driving has the primaries open further than a square-bore carb, so it will be more accurate. That is, less rich. Which means better mileage.
It also means better throttle response, because the stack velocity in the Qjet's primaries is so much higher than the stack velocity in a square-bore carburetor's primaries for the same cfm.
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I got the well known edelbrock 1406 carb elec choke and it bolted and fired up with no tuning as well. now I'm going to rebuild the old holley and sell it to make some money back. love the edel
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also I bolted it on to a near stock crate motor, only a header and intake upgrade
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