03-22-2011, 09:54 AM | #26 | |
1965 Chevy C10, 2005 4.8L/4l60
Join Date: Aug 2004
Location: DFW Texas
Posts: 8,546
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Re: Better gas mileage
Quote:
Wow! thats over $9.00 a gallon US! Would we drive our trucks if fill ups cost $180.00? YOUR DARN RIGHT WE WOULD!
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Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 support our troops! |
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03-22-2011, 11:33 AM | #27 |
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Join Date: Sep 2010
Location: hingham ma
Posts: 1,721
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Re: Better gas mileage
find a 3.08 rear gear and install it, or change out the whole rear if easier than setting up gears..
those 4.56 are killing you.. |
03-22-2011, 04:41 PM | #28 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,690
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Re: Better gas mileage
getting a 3.08 gear would be a pain and then you start getting into fab work since it would most likely be a 14 bolt later model rear.
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03-22-2011, 05:22 PM | #29 |
1965 Chevy C10, 2005 4.8L/4l60
Join Date: Aug 2004
Location: DFW Texas
Posts: 8,546
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Re: Better gas mileage
I have a 3.07/8 in my 12 bolt 72 rear.
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Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 support our troops! |
03-22-2011, 05:48 PM | #30 |
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Join Date: Feb 2007
Location: Marana, Arizona
Posts: 3,455
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Re: Better gas mileage
Couple of thoughts here.
Breathing is a factor maybeif you keep the high # gears. The easy way to get better mpg is to lower speed. Engine and vehicle. If your engine speed (rpm) is down better breathing wont mean much as it breaths plenty at low rpm's. Aero gains should be considered, like LHM said about holding your hand out the window at speed. Try holding a truck mirror vs. a sport mirror. Bed cover, Grill block, narrow tires?, vac gauge. Take a look here.... http://ecomodder.com/forum/fuel-econ...ifications.php There are a few truck guys on that site. Some of there ideas work but I wouldn't do them. Engine kill switch, teeny tiny car. Some good ideas.
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"I feel the need for speed!"... as soon as I am done with my nap. |
03-22-2011, 06:53 PM | #31 | |
Senior Member
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 7,504
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Re: Better gas mileage
Quote:
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Every 25 years I like to rebuild that 292, whether it needs it or not. |
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03-22-2011, 10:37 PM | #32 | |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,690
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Re: Better gas mileage
You have a half ton, he has a 3/4 ton. Since there's been no talk of making his a 1/2 ton truck, I can only assume he has no interest in a 12 bolt rear. If he is willing to do a suspention swap, then yes, a 3.07 (3.08 was a car gear) 12 bolt would be the way to go.
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03-23-2011, 07:24 AM | #33 |
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Join Date: Feb 2007
Location: Memphis MI
Posts: 1,851
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Re: Better gas mileage
3.42's in 14bolt SF, 8 bolt 16/16.5, any light 3/4 ton. That's how the 81 above was set up, and I could make it get 15's pretty easily. Taller tires would help, I was running about 31's.
3.23's were an option but rare. Clifford will hurt your mpg (it's more of an RPM manifold) but the headers should help slightly. It's those rear gears that are the killer. Which axle do you have, 12 bolt or Eaton?
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1987 2 ton 1982 250/TH350 beater in progress Dad's 1981 3/4 L6 3 on tree posi and no options, awaiting restoration or scrapping Plus a mess o' tractors Last edited by D13; 03-23-2011 at 07:28 AM. |
04-15-2011, 07:51 PM | #34 |
Registered User
Join Date: Jan 2007
Location: Scottsdale Arizona
Posts: 125
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Re: Better gas mileage
I'm running half ton gear and I believe 3.42's with a 2004r overdrive automatic.
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05-02-2011, 08:57 AM | #35 |
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Join Date: May 2009
Location: Waynesville, Ohio
Posts: 136
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Re: Better gas mileage
Did a test this weekend, 130 miles and ended up with 17.5 MPG.
Installed the Astro Van T5 over the winter and this was its first long drive. Very happy. I have the pertronix upgrade next to install. Plus have a new intake, split longtube headers and a Holley four barrell on the shelf in waiting Currently I have a stock intake, carb, exhaust and 3.73 gears.
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1970 C10 LWB (Grandfather's Truck) 5.3 4L60E 2012 Victory Cross Country Touring I'm not wasting money on my truck/bike, I'm helping to rescue the economy one mod at a time. |
05-02-2011, 07:52 PM | #36 |
Registered User
Join Date: Jan 2007
Location: Scottsdale Arizona
Posts: 125
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Re: Better gas mileage
That sounds respectable. I have kinda the same setup as you except with an auto trans. Just purchase a new HEI and wires for it. Keep us updated as you upgrade to your aftermarket goodies on whether the mileage goes up or down. I'm still plugging along trying to put mine together. All this rain needs to stop before I can proceed any further.
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05-16-2011, 10:39 AM | #37 |
Registered User
Join Date: Jun 2009
Location: Forest City IA
Posts: 56
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Re: Better gas mileage
My 2 cents (possible 3 cents at todays gas prices). Keep your speed down. I can get 14 MPG on the highway with a 250, 4 speed and 5.13:1 gears in a 67 C20 with the old model B carb. I have to run 60 with the engine turning over at 3500. The truck is running on the rich side with factory jetting and it has an old LMC glasspack single exhaust. Otherwise it is stock including the ignition system. Tall gear will help but you are fighting bad aerodynamics and a small engine for the load. If you gear too tall you will spend a lot of time with the powervalve open in the carb (yes even a model B has a power circuit) and your gas mileage will go away unless you are driving on flat ground with a tailwind.
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