mileage - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bman1985 · 02-16-2010, 01:44 AM

I'm planning to fix up an 82-87 c10 2wd as a daily driver. Right now I'm thinking 350 (decent build for some power) with a 700r4 and maybe 3.73 gears. What kind of mileage do you guys get?

GMC Guy · 02-16-2010, 02:27 AM

kinda depends on what set-up you're running on that 350. but i'd say 12-18 depending on how you drive.

spinem · 02-16-2010, 02:39 AM

haha i wish i got 12.... if u hit alot of greens, u can get a good 12-18... maybe 20 highway.

ocbaud · 02-16-2010, 02:48 AM

10mpg or so combined with my engine and th350 and 3.73's

:-/

C10_86 · 02-16-2010, 10:55 AM

My '86 long bed has a fresh stock 350, rebuilt Q-Jet with performer intake and a 700R4 with 3.42 rear end and I get 19-20mpg highway and 15-16 combined average.
I have gotten 21.5mpg on a 300 mile trip before. Nothing beats a properly rebuilt Q-Jet for mileage.

C10Silverado79 · 02-16-2010, 11:45 AM

Quote:

Originally Posted by C10_86

My '86 long bed has a fresh stock 350, rebuilt Q-Jet with performer intake and a 700R4 with 3.42 rear end and I get 19-20mpg highway and 15-16 combined average.
I have gotten 21.5mpg on a 300 mile trip before. Nothing beats a properly rebuilt Q-Jet for mileage.

I rebuilt a 2 bbl carb on a 250 6-cyl once but that was a lot of years ago. Can these carbs be rebuild by a rusty DIY'r or do they need to be rebuilt by a shop? Are rebuild kits available? I have never had a 4-bbl carb before.

piecesparts · 02-16-2010, 11:55 AM

Running an 84 GMC SWB, with a 385 stroker, through a 700R4, to 3.73 gears--getting 14.5 to 15 MPG on the highway. I run 28" tires on the rear and 27" on the front. My RPMs are at 2500 at about 72 MPH. I consider this a good combination, since I have a lot of hilly areas to deal with and this allows the cruise to work without a lot of hard revving to make it over the hills.

My Son's truck has a 350, 700R4, with 3.73 gears and he gets around 13.5 to 14 MPG.

Both of the 700 R4 trannys do NOT have the Lock up converters-----They were built this way.

bman1985 · 02-16-2010, 12:29 PM

Yeah, I haven't decided what I want to do with the motor exactly yet. I'm still in the looking for a truck/dreaming phase. I'm sure it won't be a stock 350, I really like the HP numbers of those edelbrock performer RPM motors but that might be a little over budget. I've also considered a 5.3 from a newer truck (which would get better mileage I assume) but I've got a 4 bolt 350 block in the garage already.

Piecesandparts-I like the black c10s in your picture there thats about what I'm looking to do, maybe some yellow stripes

GMC Guy · 02-16-2010, 01:49 PM

Quote:

Originally Posted by C10Silverado79

I rebuilt a 2 bbl carb on a 250 6-cyl once but that was a lot of years ago. Can these carbs be rebuild by a rusty DIY'r or do they need to be rebuilt by a shop? Are rebuild kits available? I have never had a 4-bbl carb before.

you can pick up a rebuild kit from your local auto parts store for around $25.

GMC Guy · 02-16-2010, 01:50 PM

Quote:

Originally Posted by C10_86

My '86 long bed has a fresh stock 350, rebuilt Q-Jet with performer intake and a 700R4 with 3.42 rear end and I get 19-20mpg highway and 15-16 combined average.
I have gotten 21.5mpg on a 300 mile trip before. Nothing beats a properly rebuilt Q-Jet for mileage.

how do you like the 700r4 and 3.42 combo? seems to do pretty well on the highway, but how's the performance around town?

C10_86 · 02-16-2010, 02:12 PM

Quote:

Originally Posted by GMC Guy

how do you like the 700r4 and 3.42 combo? seems to do pretty well on the highway, but how's the performance around town?

It's a little annoying in town since it shifts so early. You can be in 3rd gear by 20-25mph and fully locked up in O/D by 35-38mph if your very light on the pedal but I got used to it. As for highway driving I like it. It climbs hills very well and rarely shifts out of O/D with the cruise on.

C10_86 · 02-16-2010, 02:27 PM

Quote:

Originally Posted by C10Silverado79

I rebuilt a 2 bbl carb on a 250 6-cyl once but that was a lot of years ago. Can these carbs be rebuild by a rusty DIY'r or do they need to be rebuilt by a shop? Are rebuild kits available? I have never had a 4-bbl carb before.

You can do it yourself but you have to be sure the bowl is not warped. It is a common issue with Q-Jets and will cause problems if not corrected. Also if you do it yourself make sure you epoxy the well plugs in the bowl as they are prone to leaking fuel. I did not not do mine myself. I would recommend a company called Carburetor Exchange www.carb-x.com in California that most likely has the carb you need already rebuilt and ready to ship. You just send them your old one for a core exchange. Mine cost me $185.95 + shipping. It's completely rebuilt, dewarped set up to factory specs and run on a live engine before shipping. I just bolted mine on and haven't touched it since.

C10Silverado79 · 02-16-2010, 03:23 PM

Quote:

Originally Posted by C10_86

You can do it yourself but you have to be sure the bowl is not warped. It is a common issue with Q-Jets and will cause problems if not corrected. Also if you do it yourself make sure you epoxy the well plugs in the bowl as they are prone to leaking fuel. I did not not do mine myself. I would recommend a company called Carburetor Exchange www.carb-x.com in California that most likely has the carb you need already rebuilt and ready to ship. You just send them your old one for a core exchange. Mine cost me $185.95 + shipping. It's completely rebuilt, dewarped set up to factory specs and run on a live engine before shipping. I just bolted mine on and haven't touched it since.

Thanks for the info. I'm not so sure I want to do it myself so I will keep this company in mind.

bman1985 · 02-16-2010, 11:56 PM

Quote:

Originally Posted by C10_86

My '86 long bed has a fresh stock 350, rebuilt Q-Jet with performer intake and a 700R4 with 3.42 rear end and I get 19-20mpg highway and 15-16 combined average.
I have gotten 21.5mpg on a 300 mile trip before. Nothing beats a properly rebuilt Q-Jet for mileage.

what about TBI does it have any significant benefits over a carb mileage/power wise for a daily driver?

gchemist · 02-17-2010, 12:20 AM

ZZ4 will get 13-15 in the city. Drops really quick with a lead foot. 18+ MPG on the highway at 70 MPH.

Fuel injection is the way to go for a daily driver!!

bman1985 · 02-17-2010, 12:38 AM

Yeah I was starting to think that after I looked into it more. Sounds like its all benefits except for the initial install which take some more work. Is TBI any good (it seems more simple and cheaper) or do more people go with TPI systems?

gchemist · 02-17-2010, 03:10 AM

LS conversions are becoming popular. I saw an ad for a 5.3 for only $800 locally. It had 108K miles on it. Read this:http://www.hotrodlane.cc/77chevytruck/77chevy.htm

A TBI conversion is the simplest and least expensive. Stock parts are available from donor trucks or over the shelf. Read this for a TBI conversion.
http://users.sfo.com/~eagle/howell.html

For lower power grunt, TPI is good. TPI however has limitations on the top end.

D13 · 02-17-2010, 07:26 AM

TBI is good for 1-2mpg and way better cold driveability. Unless you get all the parts cheap or put 200K miles on it you'll never recover the cost of the parts. Sure is nice on cold starts though.

If you rebuilt a staged 2bbl off the integral head 250 the Qjet should be easy. Nowhere near as finicky. Buy the gallon can of cab soak (the main body probably won't fit in it by the way), 3-4 cans spray carb cleaner, and a pack of toothbrushes. IIRC needlenose, channel locks, and screwdrivers.

And don't forget to epoxy the well plugs with a gasoline and alcahol resistant epoxy.

Keith Seymore · 02-17-2010, 08:40 AM

I get 22 mpg; 4.3L V6 TBI, MY6 3 speed manual where 4th gear is a .73 overdrive, 3.73 posi axle with P235/75R15 tires.

Drive it every day, rain (or snow) or shine!

K

Dooley Dude · 02-17-2010, 09:52 AM

My truck is a little different, but I recently got some great gas mileage and I wanted to brag about it. My truck is an '85 C-30 Dooley, 350 with a TH-400, 4.10 gears and stock Q-jet. I drove it down the interstate (empty) and back with a full load of furniture in it. Speeds averaged around 60 mph. I got between 10 and 11 mpg, and I was tickled!

Your mileage may vary. I'm pretty happy with mine. My neighbor has a little F-150 with a V-6 and he gets 17. Years ago a friend of mine had a little Ford Ranger with a manual tranny and tiny 2.0 4-banger, and he consistently got only 20 mpg.

TwoFiftyShifter · 02-17-2010, 10:24 AM

Also, dont build your motor too nasty if mileage is important.

bman1985 · 02-17-2010, 10:44 AM

I'm thinkin the TBI system since its cheaper and simpler. I haven't really found much showing huge benefits of TPI over TBI.

My cousin is actually working on an 83 monte carlo that he plans to drop and LS into I guess he'd be a good source of info on that swap since hes ahead of me on his project!

--thats pretty solid mileage for a loaded up dooley!

02-16-2010, 01:44 AM	#1
bman1985 Registered User Join Date: Dec 2009 Location: Edgewater, MD Posts: 23	mileage I'm planning to fix up an 82-87 c10 2wd as a daily driver. Right now I'm thinking 350 (decent build for some power) with a 700r4 and maybe 3.73 gears. What kind of mileage do you guys get?

02-16-2010, 02:27 AM	#2
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: mileage kinda depends on what set-up you're running on that 350. but i'd say 12-18 depending on how you drive. __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

02-16-2010, 02:39 AM	#3
spinem haha, ford guys... Join Date: Feb 2007 Location: Visalia, CA Posts: 576	Re: mileage haha i wish i got 12.... if u hit alot of greens, u can get a good 12-18... maybe 20 highway.

02-16-2010, 02:48 AM	#4
ocbaud Garage Queen Material Join Date: Oct 2002 Location: USA Posts: 4,129	Re: mileage 10mpg or so combined with my engine and th350 and 3.73's :-/

02-16-2010, 10:55 AM	#5
C10_86 Registered User Join Date: Feb 2010 Location: Morgan, MN Posts: 19	Re: mileage My '86 long bed has a fresh stock 350, rebuilt Q-Jet with performer intake and a 700R4 with 3.42 rear end and I get 19-20mpg highway and 15-16 combined average. I have gotten 21.5mpg on a 300 mile trip before. Nothing beats a properly rebuilt Q-Jet for mileage.

02-16-2010, 11:55 AM	#7
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: mileage Running an 84 GMC SWB, with a 385 stroker, through a 700R4, to 3.73 gears--getting 14.5 to 15 MPG on the highway. I run 28" tires on the rear and 27" on the front. My RPMs are at 2500 at about 72 MPH. I consider this a good combination, since I have a lot of hilly areas to deal with and this allows the cruise to work without a lot of hard revving to make it over the hills. My Son's truck has a 350, 700R4, with 3.73 gears and he gets around 13.5 to 14 MPG. Both of the 700 R4 trannys do NOT have the Lock up converters-----They were built this way. __________________ Frank

02-16-2010, 12:29 PM	#8
bman1985 Registered User Join Date: Dec 2009 Location: Edgewater, MD Posts: 23	Re: mileage Yeah, I haven't decided what I want to do with the motor exactly yet. I'm still in the looking for a truck/dreaming phase. I'm sure it won't be a stock 350, I really like the HP numbers of those edelbrock performer RPM motors but that might be a little over budget. I've also considered a 5.3 from a newer truck (which would get better mileage I assume) but I've got a 4 bolt 350 block in the garage already. Piecesandparts-I like the black c10s in your picture there thats about what I'm looking to do, maybe some yellow stripes

02-17-2010, 12:20 AM	#15
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: mileage ZZ4 will get 13-15 in the city. Drops really quick with a lead foot. 18+ MPG on the highway at 70 MPH. Fuel injection is the way to go for a daily driver!! __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

02-17-2010, 12:38 AM	#16
bman1985 Registered User Join Date: Dec 2009 Location: Edgewater, MD Posts: 23	Re: mileage Yeah I was starting to think that after I looked into it more. Sounds like its all benefits except for the initial install which take some more work. Is TBI any good (it seems more simple and cheaper) or do more people go with TPI systems?

02-17-2010, 03:10 AM	#17
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: mileage LS conversions are becoming popular. I saw an ad for a 5.3 for only $800 locally. It had 108K miles on it. Read this:http://www.hotrodlane.cc/77chevytruck/77chevy.htm A TBI conversion is the simplest and least expensive. Stock parts are available from donor trucks or over the shelf. Read this for a TBI conversion. http://users.sfo.com/~eagle/howell.html For lower power grunt, TPI is good. TPI however has limitations on the top end. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

02-17-2010, 07:26 AM	#18
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: mileage TBI is good for 1-2mpg and way better cold driveability. Unless you get all the parts cheap or put 200K miles on it you'll never recover the cost of the parts. Sure is nice on cold starts though. If you rebuilt a staged 2bbl off the integral head 250 the Qjet should be easy. Nowhere near as finicky. Buy the gallon can of cab soak (the main body probably won't fit in it by the way), 3-4 cans spray carb cleaner, and a pack of toothbrushes. IIRC needlenose, channel locks, and screwdrivers. And don't forget to epoxy the well plugs with a gasoline and alcahol resistant epoxy. __________________ 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

02-17-2010, 08:40 AM	#19
Keith Seymore Registered User Join Date: May 2009 Location: Motor City Posts: 9,179	Re: mileage I get 22 mpg; 4.3L V6 TBI, MY6 3 speed manual where 4th gear is a .73 overdrive, 3.73 posi axle with P235/75R15 tires. Drive it every day, rain (or snow) or shine! K __________________ Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/ Last edited by Keith Seymore; 02-17-2010 at 08:41 AM.

02-17-2010, 09:52 AM	#20
Dooley Dude Registered User Join Date: Jan 2009 Location: Richmond, VA Posts: 53	Re: mileage My truck is a little different, but I recently got some great gas mileage and I wanted to brag about it. My truck is an '85 C-30 Dooley, 350 with a TH-400, 4.10 gears and stock Q-jet. I drove it down the interstate (empty) and back with a full load of furniture in it. Speeds averaged around 60 mph. I got between 10 and 11 mpg, and I was tickled! Your mileage may vary. I'm pretty happy with mine. My neighbor has a little F-150 with a V-6 and he gets 17. Years ago a friend of mine had a little Ford Ranger with a manual tranny and tiny 2.0 4-banger, and he consistently got only 20 mpg.

02-17-2010, 10:24 AM	#21
TwoFiftyShifter Registered User Join Date: Nov 2008 Location: Gwinnett GA Posts: 1,803	Re: mileage Also, dont build your motor too nasty if mileage is important. __________________ 1982 K10 SWB 1987 V20 - Sold - Doh!

02-17-2010, 10:44 AM	#22
bman1985 Registered User Join Date: Dec 2009 Location: Edgewater, MD Posts: 23	Re: mileage I'm thinkin the TBI system since its cheaper and simpler. I haven't really found much showing huge benefits of TPI over TBI. My cousin is actually working on an 83 monte carlo that he plans to drop and LS into I guess he'd be a good source of info on that swap since hes ahead of me on his project! --thats pretty solid mileage for a loaded up dooley!



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