Rear end gears

Discussion in '1978 - 1981 Specific' started by Clifford Barfield, Nov 25, 2019.

  1. Clifford Barfield

    Clifford Barfield New Member

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    I have a 1979 Camaro RS. It has 2:41 rear end gears. I kept the original 305 motor but beefed it up with a mild cam, Vortec heads, 650 carburetor and dual exhaust. I swapped the T350 for a 700R4. Now I wan to change the rear end gears. I am deciding between the 3:08 and the 3:42's. I have the original rims (14") and tire height is 25".
    I like the power of the 3:42 gears but don't want to lose my ability to cruise on the highway at 80. Any ideas?
     
  2. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    The 3.42 gear will work fine with your 700-R4 transmission. I'm running 3.73 gears with a much taller tire. You're probably lugging that engine real hard with those 2.41 gears.

    BTW, welcome to NastyZ.
     
    buick skylark likes this.
  3. CDesperado

    CDesperado Veteran Member Lifetime Gold Member

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    I went with 3.73 gears and a 700R4 tranny. Im pretty happy with the combo so far.
     
  4. ULTM8Z

    ULTM8Z Veteran Member

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    With 3.42 and th700r4, I'm only doing about 2400 rpm at 70 mph.
     
  5. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    3.42 gears with a 700r4 (0.70 OD) gives you a final gear ratio of 2.39.

    Your highway cruise RPM will be virtually identical to the 2.41 gears you have now with your TH350.

    A 3.73 ratio would also be a good choice as your highway RPM would only go up about 10%.
     
  6. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Anyone else notice this is OP's first and only post, and last activity is post date. We've had a couple of these lately.
     

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