I have a 226 V6 and the PO has fitted a 4 barrel carb to it. According to what I read, the engine first came with a 2 barrel carb. I am getting 20 MPG on the highway, will I get better mileage with a 2 barrel?

Also, is the base for the 2 barrel and for the 4 barrel the same or has the PO also replaced the intake manifold??

For the 4v carb, you also have a different intake, so to switch back, you will need a 2v intake. The theory is: a 4BBL will get better gas mileage when using the primaries because they are smaller, so as long as you keep your foot out of it, it should be fine. Also, when you do floor it, you will have a little more power. :-D

Short answer No.


That engine is doing all it can to get that elky down the road. 20mpg is nothing to be ashamed of.

If you want better (doubt it would be much different) mileage and drivability I'd go to FI. But if yours is all in good shape just drive it.

Thanks guys, that was what I suspected. As long as its working I wont touch it and when I do I will go with a TBI unit.

again the lost post discribed what sounded like a 4 bbl lock out device.

I do not know if 4bbls came on V6?
But 20 MPG is great wish I got it.

I hope you have a fresh inspection sticker cause getting on base can be a problem. T

I do not know if 4bbls came on V6?
But 20 MPG is great wish I got it.


You can pull out your V8 and put in a V6 :baa: Or get rid of some power, or change gear ratios or transmission and change gear ratios.

Efficiency of a power plant is based on the tune. A well tuned Power plant is efficient. May not always get what can be "generally" considered good Mileage but it's getting the best for it's power range and other factors. There is really little reason that a V8, say a 350, shouldn't get 20 MPG and still produce 300 or so HP. 0-60 or 1/4 times can effect that lot. Drive train is a major factor. 8-) :lol:

Mine don't get 20 but then I know my 76's power (GMPP ZZ383) plant is not tuned to be efficient just yet. I'm running a little rich but still get about 15-17 Mpg @ over 400 Hp output.

Your '83 229 was originally equiped with the electronic DualJet carb. The original EPA estimate for highway mileage was 28 mpg. Of course that was back when they tested at 50 mph for "highway" speeds.

I have a 1980 non-electronic DualJet on my 229 (rebuilt to stock specs, daily driver), which was originally rated at 26 mpg highway. The best I have ever seen is 24 mpg on a 500 mile trip up I95 (with the a/c running). Normally I see 20-21 mpg in a mix of highway/city driving.

The Chevy V6 engines only came with 2 barrel Rochester DualJet carbs from the factory. They used an aluminum single plane intake manifold, and they only fit 2bbl carbs. (There were GM performance parts back in the day for the V6, but I doubt any are around now).

It seems like you are getting decent mileage already, but if the PO has done a poor job adapting a 4bbl carb to this engine, and you want to try for better economy, you may want to go back to an original type. I don't think that engine gained any performance with a 4bbl carb (especially just using the primaries) and the Dualjet will be tuned for the V6 application.

A FI setup would get better mileage, but I suspect it would not get much more than an original computer controlled carb. It may be worthwhile and less expensive to put back the stock fuel system.

Sounds like tire shredding take-off performance isn't your main objective, so if you're getting 20 MPG now, I'd just leave things as they are and consider reverting to the stock setup only when it's too expensive to maintain the current one.

One tool you can use to see if your air/fuel ratio is about right (and not wasting fuel) under cruising conditions is the car's O2 sensor, if it's still in the exhaust system. Hook a $20 A/F ratio meter to it and watch to see if it shows mostly green most of the time or mostly red most of the time. Ideally, you'll want it red 50% of the time and green 50% of the time (don't expect it to stay still, or in the middle range. It's a narrow band sensor and is best used for registering on either side of the chemically ideal mixture (14.7:1)). If you determine the average mixture's off some, then a change to the carb's primary jets might be called for.

If you don't want to spend the bucks on an A/F ratio gage, just measure the sensor's output voltage with a digital voltmeter. If memory serves, you're looking ideally for 0.57 volts, as I recall, which translates to 14.7:1 A/F ratio. (You experts out there please confirm).

One other thing. More power is made when the ratio is richer than 14.7:1. Max power is made around 12 or 12.5:1. So, my suggestion is if you're going to er on the A/F ratio, leaving it a little rich is better than leaving that leaving it even a little bit lean.

Hope it helps.

Thanks, the O2 metering thing sounds like just what I need. I have a gauge that is designed to read the O2 output on a meter on the dash it is designed to show an average to get rid of the fluxuations. I doubt that the O2 sensor is there anymore but I will look and see. If not a $20 O2 sensor would be well worth the investment. I might even have one laying on the bench that works. Then a dash mounted mixture adjustment might be a good addition also.

Thanks for the suggestion.

Thanks, the O2 metering thing sounds like just what I need. I have a gauge that is designed to read the O2 output on a meter on the dash it is designed to show an average to get rid of the fluxuations. I doubt that the O2 sensor is there anymore but I will look and see. If not a $20 O2 sensor would be well worth the investment. I might even have one laying on the bench that works. Then a dash mounted mixture adjustment might be a good addition also.

Thanks for the suggestion.

Thanks, the O2 metering thing sounds like just what I need. I have a gauge that is designed to read the O2 output on a meter on the dash it is designed to show an average to get rid of the fluxuations. I doubt that the O2 sensor is there anymore but I will look and see. If not a $20 O2 sensor would be well worth the investment. I might even have one laying on the bench that works. Then a dash mounted mixture adjustment might be a good addition also.

Thanks for the suggestion.

This is the second time I have had a problem with sending three copies. Something strange going on in my computer. SORRY.

Granted it was a stroke of brilliance on my part, but thanking me three times is bordering on excessive even for me, Mr. egocentric. :lol:

Seriously, I hope the hardware's all there and it works out for you.

I just came up from the garage and I found three O2 sensors and I also found my gauge. I had never installed the gauge. It is a 2.25" diameter gauge with a digital readout of 4 digits. The instructions are in the box that it will work with ANY O2 sensor and I think it reads in Volts. Supposedly it is damped to make it easier to read. Now all I have to do is drill a hole in the exhaust pipe just down from the header and tap it to match and screw this thing in. I hope the thin pipe will have enough threads so that it wont blow the sensor out.

drill a hole and weld the appropriate nut there

i have a 1983 el camino conquista and i have a v8 in it now i would like to no what gear ratios are in my rear end would u think a 373 from a monte and a 700 r 4 would be a good power train swap or do u no sumthing that would be a better choice for me thanks james

"Hook a $20 A/F ratio meter to it and watch to see if it shows mostly green most of the time or mostly red most of the time. Ideally, you'll want it red 50% of the time and green 50% of the time (don't expect it to stay still, or in the middle range."




Where can I buy one of those A/F meters?
Using a meter are those readout #'s fixed or do the vairy with speeds?
You should be able to tail pipe them also with out cats.
T