383 sbc gas milage
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Posts: 688
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From: va fairfax
Car: 85 camaro z28
Engine: 305
Transmission: auto to manaul
383 sbc gas milage
how much will my gas milage change from 305 to 383 sbc? its already pretty bad
Last edited by five7kid; Nov 5, 2008 at 11:33 AM. Reason: language
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: 383 sbc gas milage
Depends on what gears you've got, what cam you use, what induction system you have, how it's tuned, and how you drive it.
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Joined: Oct 2002
Posts: 9,067
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: 383 sbc gas milage
All else being equal, it shouldn't be much different. The 5.0 TPI and 5.7 TPI ratings were basically the same, I think the 5.7 was like 1mpg lower city and hywy, 383 wouldn't be much different than the 5.7
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From: Wittman,Az
Car: 86 IROC-Z, '71 RS
Engine: 305 TPI/ 350
Transmission: 700R4/TH350
Re: 383 sbc gas milage
It might even improve... With more horsepower on demand, you will put your foot into it less... If that makes any sense...
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Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
If you're getting poor mileage with the 305, you've got something wrong. Why would you want to build a 383 and keep what's wrong?
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Joined: Mar 2005
Posts: 1,665
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From: Benzie, MI
Car: 91 rs
Engine: Blow through 383, 10 psi, xr288hr
Transmission: Manual th350 ATI 3000
Axle/Gears: 3.50 9"
Re: 383 sbc gas milage
You may see an increase if the engine's output is increased in the area that you spend most of your rpm's. However a 350 tpi should have more than enough tq to get the car moving well at low rpms.
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