New 71
Fleet Mechanic
Joined: Jun 2009
Posts: 1,312
Likes: 327
From: San Antonio, TX
The Holley Truck Avengers look nice but I think a regular old Quadrajet is what I’ll be using. I have maybe half a dozen on the shelf and they’re supposed to be great off road carbs. Just need to use an adapter or an Offy intake for a spreadbore.
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Moderator & parts slinger
Joined: Feb 2007
Posts: 50,172
Likes: 5,789
From: S/W Missouri, Polk county
The ol 71 came with a very old, very very leaky 4bbl Quadrajet on it. It probably had not ran in many months or even longer...like a year or more. The owner drove (in a big open field), so I could make sure the trans shifted and the xfer case worked. I had to constantly dump gas in the carb during the test drive.
With no windshield and once un pinned the fiber glass hood and took it off, I poked a small hole in a water bottle cap, so I could drip fuel in it, while leaning thru the WS frame. We made it a small lap and then 1/2 way back to the house it finially gave up running all together. A backhoe pushed it on the trailer.
They say you can even run the Quadrajet mounted backwards. Too run the 2 big barrels all the time and the 2 smaller ones when needed, in stead of the other way around. Or some suck talk like that, at least that is urban legend.
AI can I run a Quadrajet carb backwards? "Yes, you can run a Rochester Quadrajet carburetor backwards (rotated 180*) on an engine, a trick sometimes used in off-road applications to prevent fuel slosh/stumbling due to its center-mounted fuel bowl. This setup requires a special adapter to match the bolt pattern and a modified throttle cable, but it functions well. "
While common in specialized off-road vehicles (e.g., old Broncos), this is not a typical street application setup.
Key considerations for running a Quadrajet backward include:
https://classicbroncos.com/forums/th...uestion.47864/
I slapped on a 4 bbl Edelbrock on, since I had one on the shelf and got to working on all the rest. When that carb almost killed me, cause the Bronco died on a VERY steep long down hill. No running Bronco='s NO PS, NO power brakes ='s almost dieing. I went to a MC 2bbl for a while, yes it ran great, but just not enough power.
So after some off road tricks to the Edelbrock, that made it better but still not all that. I ran across a smoking deal on the Holley Off Road carb. It is great for of roading, but crappy IMO on flat terrain.
With no windshield and once un pinned the fiber glass hood and took it off, I poked a small hole in a water bottle cap, so I could drip fuel in it, while leaning thru the WS frame. We made it a small lap and then 1/2 way back to the house it finially gave up running all together. A backhoe pushed it on the trailer.
They say you can even run the Quadrajet mounted backwards. Too run the 2 big barrels all the time and the 2 smaller ones when needed, in stead of the other way around. Or some suck talk like that, at least that is urban legend.
AI can I run a Quadrajet carb backwards? "Yes, you can run a Rochester Quadrajet carburetor backwards (rotated 180*) on an engine, a trick sometimes used in off-road applications to prevent fuel slosh/stumbling due to its center-mounted fuel bowl. This setup requires a special adapter to match the bolt pattern and a modified throttle cable, but it functions well. "
While common in specialized off-road vehicles (e.g., old Broncos), this is not a typical street application setup.
Key considerations for running a Quadrajet backward include:
- Off-Road Benefits: The center-mounted float bowl prevents stalling at steep, extreme angles.
- Adapter Required: A specific adapter is needed to mount the spread-bore carburetor backward on a standard intake manifold.
- Throttle Cable Issues: The throttle linkage moves to the front, necessitating a longer, custom-routed throttle cable to reach it.
- Fuel Inlet Access: The fuel inlet will move to the rear of the engine, requiring new fuel line routing.
https://classicbroncos.com/forums/th...uestion.47864/
I slapped on a 4 bbl Edelbrock on, since I had one on the shelf and got to working on all the rest. When that carb almost killed me, cause the Bronco died on a VERY steep long down hill. No running Bronco='s NO PS, NO power brakes ='s almost dieing. I went to a MC 2bbl for a while, yes it ran great, but just not enough power.
So after some off road tricks to the Edelbrock, that made it better but still not all that. I ran across a smoking deal on the Holley Off Road carb. It is great for of roading, but crappy IMO on flat terrain.
Fleet Mechanic
Joined: Jun 2009
Posts: 1,312
Likes: 327
From: San Antonio, TX
The ol 71 came with a very old, very very leaky 4bbl Quadrajet on it. It probably had not ran in many months or even longer...like a year or more. The owner drove (in a big open field), so I could make sure the trans shifted and the xfer case worked. I had to constantly dump gas in the carb during the test drive.
With no windshield and once un pinned the fiber glass hood and took it off, I poked a small hole in a water bottle cap, so I could drip fuel in it, while leaning thru the WS frame. We made it a small lap and then 1/2 way back to the house it finially gave up running all together. A backhoe pushed it on the trailer.
They say you can even run the Quadrajet mounted backwards. Too run the 2 big barrels all the time and the 2 smaller ones when needed, in stead of the other way around. Or some suck talk like that, at least that is urban legend.
AI can I run a Quadrajet carb backwards? "Yes, you can run a Rochester Quadrajet carburetor backwards (rotated 180*) on an engine, a trick sometimes used in off-road applications to prevent fuel slosh/stumbling due to its center-mounted fuel bowl. This setup requires a special adapter to match the bolt pattern and a modified throttle cable, but it functions well. "
While common in specialized off-road vehicles (e.g., old Broncos), this is not a typical street application setup.
Key considerations for running a Quadrajet backward include:
https://classicbroncos.com/forums/th...uestion.47864/
I slapped on a 4 bbl Edelbrock on, since I had one on the shelf and got to working on all the rest. When that carb almost killed me, cause the Bronco died on a VERY steep long down hill. No running Bronco='s NO PS, NO power brakes ='s almost dieing. I went to a MC 2bbl for a while, yes it ran great, but just not enough power.
So after some off road tricks to the Edelbrock, that made it better but still not all that. I ran across a smoking deal on the Holley Off Road carb. It is great for of roading, but crappy IMO on flat terrain.
With no windshield and once un pinned the fiber glass hood and took it off, I poked a small hole in a water bottle cap, so I could drip fuel in it, while leaning thru the WS frame. We made it a small lap and then 1/2 way back to the house it finially gave up running all together. A backhoe pushed it on the trailer.
They say you can even run the Quadrajet mounted backwards. Too run the 2 big barrels all the time and the 2 smaller ones when needed, in stead of the other way around. Or some suck talk like that, at least that is urban legend.
AI can I run a Quadrajet carb backwards? "Yes, you can run a Rochester Quadrajet carburetor backwards (rotated 180*) on an engine, a trick sometimes used in off-road applications to prevent fuel slosh/stumbling due to its center-mounted fuel bowl. This setup requires a special adapter to match the bolt pattern and a modified throttle cable, but it functions well. "
While common in specialized off-road vehicles (e.g., old Broncos), this is not a typical street application setup.
Key considerations for running a Quadrajet backward include:
- Off-Road Benefits: The center-mounted float bowl prevents stalling at steep, extreme angles.
- Adapter Required: A specific adapter is needed to mount the spread-bore carburetor backward on a standard intake manifold.
- Throttle Cable Issues: The throttle linkage moves to the front, necessitating a longer, custom-routed throttle cable to reach it.
- Fuel Inlet Access: The fuel inlet will move to the rear of the engine, requiring new fuel line routing.
https://classicbroncos.com/forums/th...uestion.47864/
I slapped on a 4 bbl Edelbrock on, since I had one on the shelf and got to working on all the rest. When that carb almost killed me, cause the Bronco died on a VERY steep long down hill. No running Bronco='s NO PS, NO power brakes ='s almost dieing. I went to a MC 2bbl for a while, yes it ran great, but just not enough power.
So after some off road tricks to the Edelbrock, that made it better but still not all that. I ran across a smoking deal on the Holley Off Road carb. It is great for of roading, but crappy IMO on flat terrain.
I recently bought 60 or so vintage carburetors for $500. It was from a shop that closed down and they never threw away carburetors they removed. Ended up with a bunch of Q-jets and Carters, including a Q-jet that I sold for $500 (390 hp Corvette carb), Motorcraft 2bbl and 4bbl, several Autolite 4100's, a few Holleys, and about 10 Edelbrocks. Sold everything except for most of the Q-jets, and a few look like they've been rebuilt and never installed. Figure I might as well give 'em a shot since I have a bunch and they're supposed to work well.
Thread Starter
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Moderator & parts slinger
Joined: Feb 2007
Posts: 50,172
Likes: 5,789
From: S/W Missouri, Polk county
Yes it looks like you are busting at the seams with carburetors. I guess I need to do the research and rebuild that Quadrajet and see how well it works backwards.
Thread Starter
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Moderator & parts slinger
Joined: Feb 2007
Posts: 50,172
Likes: 5,789
From: S/W Missouri, Polk county
Well I got a little side tracked other than pulling the Bronco out of the garage for the last few weeks. So now have a 3 ton mini split installed in the garage and have been cleaning like a mad man in there to get my garage back. I had turned a 30' work bench into a 30' storage shelf. Of course now that I cleaned it, I can not find anything.
Last edited by 77&79F250; Apr 19, 2026 at 10:04 PM.
Thread Starter
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Moderator & parts slinger
Joined: Feb 2007
Posts: 50,172
Likes: 5,789
From: S/W Missouri, Polk county
Started it and backed it out of the garage again... (to put a dang pool table IN the garage) for temporary storage or at least until the pool room is done. So now I am jamming on getting it done, so I can get the garage back. I also have a stack of T&G siding, a 12' butcher block counter top, some cabinets, bar, mini fridge all in the way. But at least I got the Bronco BACK IN the garage with all that stuff.
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