Can I change a 4 barrel carburator to a 2 barrel carburator?

Question

What is involved in changing the carburator on my engine from a 4 barrel to a 2 barrel? I understand that I will give up some of the power but I hope to gain better gas milege. I have a Dodge 360 in a 1981 Transmaster motorhome.

Answer 1

Yes, a two barrel carb. will just bolt up--no need to change the intake manifold. Problem is --that a 4 barrel has better metering than a 2 barrel. not only would you have a difficult time getting the engine to pass emissions ( why the 2 barrels faded away before the 4 barrels), your fuel mileage would go down, and your power would go down.
the freeway /highway speed was 55 when this was made. now its 65/75 mph. If you change your rear end ratio you will lose acceleration. it would be better to get a transmission with a strong over-drive section, or a "GEAR VENDER" over-drive unit installed. that bolts to the rear of most transmissions.

Answer 2

What kind of carburetor is on your car now? I.E Holley, Rochester, etc. Second question is, why would you want to change to a 2 barrel? You will actually get better gas millage with a 4 barrel than with a 2 barrel, as long as you don't get on the gas hard enough to open the secondaries. Now to answer your question, you can buy an adapter plate that will let you bolt a 2 barrel on top of your intake manifold, but the fuel line, throttle linkage, or cable, transmission kickdown linkage and vacuum lines won't match up.

Answer 3

It's a bolt up, but you'll need some parts in addition to the carb. You would need to find a 2bbl manifold. There are differences in the accelerator linkage that you would need to work out, depending on the model.

You may not gain much in fuel economy for all the work involved. It just takes a lot of fuel to move that beast.

You may want to consider a change of rear axle ratio, rather than the carb swap. Switching to a higher (numerically lower) ratio will save fuel. I don't know what sort of axle is in your motorhome, but say it's a Dana 44. If you went from a 3.54 ratio to a 3.07, you would save 10-15% on fuel, at the expense of acceleration. A drivetrain specialist should be able to do this at reasonable cost.

Answer 4

yes you can as long as you get either the 2 barrel intake manifold or block off plate,but u may actually lose more gas milage because you wont have the power u need to pull it down the road.remember you only use the four barrel on demand not all the time

Answer 5

You will probably need a 2bbl intake manifold as well. I dont know if you will accomplish your goal by doing that in a motorhome. I would think you could bump your mpg slightly if you went with a smaller 4bbl that was installed and tuned by a competent shop. You could also install headers and a better dual exhaust that isnt as restrictive as the factory set up.

Answer 6

You would need to change the intake manifold to a two barrel. This would require intake manifold gaskets also exhaust manifold gaskets. Your exhaust is attached to your intake manifold. Also other odds and ends and your time to do all the work. It isn`t worth the money. You could buy a lot of gas for the money it would cost to do it. So if it ain't broke don`t fix it.

Answer 7

you dont always use the 4 barrel a motor home is so heavy a 2 barrel may not give u enough power to pull it down the road there for needing more gas to get up to speed

Answer 8

Yes you can. A different intake manifold is required unless you get an adapter but it can be done although I,ll bet the difference in mileage would be negligible.