My 78 Custom Deluxe gets a new gear ratio

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filmsmurf

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Colorado Springs
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Christopher
Truck Year
1978
Truck Model
C10
Engine Size
4.1
I am completing my first major mechanical step on my truck. Replacing the 3.75 ratio with a 3.08. Here's a before pic of the 3.75. I'll post the after picture, Friday.

PS, also replacing that nasty bearing...
 

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cstew47

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colombia
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craig
Truck Year
1978
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K5
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383
Are you planning for highway driving?
 

80BrownK10

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Greenwood, SC
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Nate
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1980
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K10
Engine Size
350
I am completing my first major mechanical step on my truck. Replacing the 3.75 ratio with a 3.08. Here's a before pic of the 3.75. I'll post the after picture, Friday.

PS, also replacing that nasty bearing...
Is 3.75 even a ratio used?
 

80BrownK10

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Nate
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1980
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K10
Engine Size
350
Guessing 3.73
I kind of thought 3.73 was all that made sense as a common ratio but I didn't know if some aftermarket performance drag set or something could be that ratio...but mathematically with the diameter of the ring gear and pinion that's probably an impossible ratio to achieve? :33::evillol:
 

ali_c20

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Austria
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Alexander
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1974, 1979
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C20, K5
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350, 350
I am completing my first major mechanical step on my truck. Replacing the 3.75 ratio with a 3.08. Here's a before pic of the 3.75. I'll post the after picture, Friday.

PS, also replacing that nasty bearing...
You have to keep us posted how much the mpg changes. I have 4.10 rear end in my c20 with a 14 bolt, may be worth changing the gears as I'm not hauling stuff and don't tow any trailers.
 
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