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#1 |
Registered User
Join Date: Nov 2008
Location: San Jose Ca
Posts: 265
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is 10 mpg normal?
my trucks is a stock 350 with a turbo 350 behind it. is 10 mpg normal? I was told and it looks like it that the motor is a chevy crate.
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#2 |
Between Trucks...
Join Date: Mar 2002
Location: Los Angeles, CA.
Posts: 3,830
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Re: is 10 mpg normal?
Yes.
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Beat it to fit, Paint it to match... ![]() |
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#3 |
Registered User
Join Date: Apr 2000
Location: new mexico
Posts: 948
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Re: is 10 mpg normal?
That is about average for all of mine. It does have the wind resistance of a brick!
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1972 3/4T 4x4 Chevrolet (383) 1971 c-10 SWB (400 sb) 1972 4x4 Blazer 1969 SWB 4x4 GMC Projects: 1972 stepside 4x4 http://67-72chevytrucks.com/vboard/s...d.php?t=280132 http://67-72chevytrucks.com/vboard/s...d.php?t=285952 http://67-72chevytrucks.com/vboard/s...d.php?t=553672 http://67-72chevytrucks.com/vboard/s...d.php?t=522704 |
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#4 |
Registered User
Join Date: Nov 2008
Location: San Jose Ca
Posts: 265
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Re: is 10 mpg normal?
LOL god I need a 700r in it
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#5 |
Grandpa in the rustmobile...
Join Date: Nov 2008
Location: Spokane WA/Viola TN
Posts: 11,422
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Re: is 10 mpg normal?
wat would u get with 700r4
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John Goose-1968 C10 355,9.32-1CR, Vortec Heads ,262 voodoo, 3.73:1 3OTT (HS ride/beater/farm truck) http://67-72chevytrucks.com/vboard/s...d.php?t=317684 Grams 53-1953 Chevrolet Belair http://67-72chevytrucks.com/vboard/s...=1#post4327784 1969 Chevy C10 Shortbed 4.5/6?" Frame off resto http://67-72chevytrucks.com/vboard/s...d.php?t=548136 1999 Toyota Tacoma 4x4 |
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#6 |
Registered User
Join Date: Nov 2008
Location: San Jose Ca
Posts: 265
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Re: is 10 mpg normal?
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#7 |
Eat My Rust
Join Date: Jan 2007
Location: Cypress, Texas
Posts: 3,362
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Re: is 10 mpg normal?
Yeh, if you do any freeway driving, the 700R4 will do you good. But 10 mpg is about normal.
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#8 |
I have a radical idea!
Join Date: Jan 2005
Location: Sweet Home Alabama!
Posts: 6,513
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Re: is 10 mpg normal?
I don't know what your truck is (C-10 or C-20?) and I don't know your gear ratio, but all of the trucks I've had with 350's/TH350's and 3.08's got better than that. I get around 14 - 15 in my red '69 SWB 350/TH350 and just slightly less (oddly enough) in my blue '69 SWB 250/3OTT. I've has others that get 12 - 13, but I never had one that gets 10 unless it was 3.73 geared 1/2 ton or a 3/4 ton or bigger. I don't putt around like grandpa, but I don't drive like I did when I was younger either.
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'67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club! |
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#9 |
PROJECT 7DEUCE
![]() Join Date: Dec 2002
Location: GRANTS PASS OR
Posts: 21,608
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Re: is 10 mpg normal?
My blazer gets about 10 and its like pushin a brick through water..
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GO BIG GREEN ![]() MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P.. |
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#10 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: is 10 mpg normal?
10 - 12 is average. http://67-72chevytrucks.com/vboard/s...d.php?t=172346
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#11 |
Hollister Road Co.
Join Date: Apr 2005
Location: Houston
Posts: 6,134
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Re: is 10 mpg normal?
I was getting 10 down hill. I put a Holley spread bore on it and jetted it back to 58's added an 1-5/8 phenolic spacer. R45ts plugs at .050 with one of those white's speed shop HEI's. I get 13 now. I have a 700r4 to put in and hoping for 16-17.
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#12 |
The Early Chevy Van Man
Join Date: Dec 2008
Location: Seattle, WA
Posts: 76
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Re: is 10 mpg normal?
10 mpg is normal... just for comparison, my '99 silverado is not much better. its a 2500 4x4 extended long bed with the 6.0 and I get 12-13 on the highway
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64 Chevy Van 65 GMC Handi-Van 99 2500 silverado 4x4 ext cab |
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#13 |
Senior Member
Join Date: Sep 2004
Location: Terrell, TX
Posts: 1,967
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Re: is 10 mpg normal?
I'll chime in with that being normal as well. I can't imagine getting more than 12 unless you drive like grandpa and never break 30mph. My best numbers with a new motor and good tuning is 11.
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Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps. |
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#14 | |
Registered User
Join Date: Feb 2004
Location: Albany, NY
Posts: 522
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Re: is 10 mpg normal?
Quote:
I got up to 13 with a Edel carb #1404 on a 327/th350 The 1404 is sized for a 305 and rated for milage, not performance. It's an easy swap for a long trip. Newer big trucks aren't doing much better. My old boss' '02 2500 quad cab longbed SRW gets around 12 on the highway.
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RN U OVR |
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#15 |
Senior Member
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Location: Austin, TX
Posts: 1,079
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Re: is 10 mpg normal?
I have a Holley 600 vacuum secondary with the black secondary spring(keeps the secondarys closed 90 percent of the time) and the best i got was 12.5 Highway, but i stopped checking my mileage when gas prices went down
P.S. i got 9.8 with the A/C on
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-- Josh Instagram: @americanmusc1e OLD SKOOL-- 1970 C10. 454/Th400/3.07 posi Build Thread FARM TRUCK----1949 Chevrolet 3800 Power Wagon Hauler Build Thread 1999 4wd OBS Tahoe - daily. DM me if you can't see photos i posted |
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#16 |
Gone to greener pastures
![]() Join Date: May 2007
Location: Gateway to the Delta
Posts: 7,354
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Re: is 10 mpg normal?
I have a 350 in my Chevy and a 402 in my GMC; both with 4.11 gears.
Both of them get around 10 MPG combination city/freeway driving, & about 13 MPG cruising the freeway & staying out of the secondaries. Having the aerodynamics of a barn doesn't help a whole lot, to be sure.
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'69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck |
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#17 |
Senior Member
![]() Join Date: May 2002
Location: Hammond, WI
Posts: 1,804
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Re: is 10 mpg normal?
I normally get 11.75 to 12. that's with a stock 350/th400 and 3.08's posi. now if i run the a/c, i get around 10, but i'd rather go with the windows down. i'm changing to a 355 and 700r4 this weekend, so if i've done my calculations correctly, i'll be sitting at 16 or 17 mpg after the swap.
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Mike 2001 Dakota R/T - Silver CC - 1 of 1671 •360 w/46RE •392 limited slip 1972 Chevy Suburban - Turquoise/Black 1969 Chevy C/10 - Blue LWB •350 w/ 700R4 •3.73 posi •PS PB A/C - SOLD ![]() Using your turn signal is not "giving information to the enemy" 67-72 FAQ |
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#18 |
Registered User
Join Date: Oct 2008
Location: Brighton, TN
Posts: 1,267
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Re: is 10 mpg normal?
I had a 4wd 79 blazer that my dad gave me that had a sb400 in it that was completely stock. I got 9mpg no matter if you were pulling a 16ft trailer with a 1972 chevy truck or just driving it down the road. After awhile the quadrajet started to leak and rather than buy a kit to rebuilt it i had a carter afb I threw on there cause it was laying around and it jumped up to about 15.5-16mpg. I loved that blazer. Had to much cancer to try and save though. Good ol nebraska truck.
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A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together. |
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#19 | |
FarmBoy.
Join Date: Feb 2005
Location: Rhinelander, WI
Posts: 1,103
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Re: is 10 mpg normal?
Maybe it's my little engine, or the gears or...something, but 10, in my opinion, is fairly low.
My truck, even as tired as it is, gets a solid 15, with jaunts up to 17-19 if the weather and gas is good, and I only drive highway with minimal hot rodding. More info would help, but, like the other guys said, it's normal...just, not with my limited experience. -Sam.
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1969 GMC C1500. long fleet. 307. 3 on the tree. 3.07 gears. Oliver green. Bent and bruised. Daily Driver. Quote:
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#20 |
Registered User
Join Date: Nov 2008
Location: San Jose Ca
Posts: 265
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Re: is 10 mpg normal?
there an easy way to find the gear ratio for my rearend?
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#21 |
Registered User
![]() Join Date: Feb 2000
Location: Georgetown, KY, USA
Posts: 631
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Re: is 10 mpg normal?
The quickest way to check your gear ratio is to jack up both rear tires, then turn the drive shaft and count the turns it takes to rotate the tires one full turn. make sure both tires are turning. So then 3 - 3/4 turns of hte drive shaft for 1 rotations of the the tires is a 3.73 gear. a little over 4 is probably a 4.11, a little over 3 is probably 3.08.
You also can look at the glove box sticker, it may have it listed if it is still there and the rearend hasn't been swapped out. Oh! I have a 350 / 400t w/ 3.73 gear and it only got 12mpg. I installed a 305 (from a 86 chevy) with HEI and the best I could ever get was 13-13.5 on the highway running 65-70. Like everyone else it really does not matter if it was loaded or not.... Last edited by Woody; 03-17-2009 at 03:21 PM. Reason: added more info |
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#22 | |
Registered User
Join Date: Nov 2008
Location: San Jose Ca
Posts: 265
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Re: is 10 mpg normal?
Need some help- Im confused. I just jacked up the truck - I kept one tire from not moving I get 1 and 1/3 tire spin to one drive line spin. the truck is to have posi from what the spid shows but when I turned the tire the other side would spin in the other direction.
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Last edited by tekno62; 03-22-2009 at 09:09 PM. Reason: cant type |
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#23 | |
I built it
Join Date: Sep 2008
Location: Bakersfield ca
Posts: 744
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Re: is 10 mpg normal?
Quote:
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'72 k10 lwb 454, th400, 205, d44ft, 12b rear, 4in skyjacker, 35x12.5-15 superswampers, 4.56, blazer tank. painless wiring harness '98 dodge 3500 12v 5sp 4x4. the truck that actually runs |
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#24 |
Registered User
Join Date: Nov 2008
Location: San Jose Ca
Posts: 265
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Re: is 10 mpg normal?
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#25 |
Registered User
Join Date: Nov 2008
Location: San Jose Ca
Posts: 265
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Re: is 10 mpg normal?
the spid just says positraction rr axle
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