# 1970 Chevrolet Malibu Classic - Gear ratio help

**URL:** <https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, transmissions\
**Created:** [August 29, 2022, 2:04pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097 "2022-08-29T14:04:17Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![madhatr925](https://avatars.discourse-cdn.com/v4/letter/m/7feea3/32.png) [@madhatr925](https://community.cartalk.com/u/madhatr925)\
**Post date:** [August 29, 2022, 2:04pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/1 "2022-08-29T14:04:17Z")

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My chevelle has a 373 gear in the rear end , I run about 3000 rom at 70 miles per hour , would like to get it down to about 2200 rpm at 70 mpm what gear ratio would that be ?

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**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\
**Post date:** [August 29, 2022, 7:04pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/2 "2022-08-29T19:04:41Z")

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[Calculate RPM for Given Speed(MPH), Rear Gear Ratio, and Trans Gear Ratio (purperformance.com)](https://purperformance.com/p-29669-rpm-calculator.html)

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**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\
**Post date:** [August 29, 2022, 7:41pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/3 "2022-08-29T19:41:30Z")

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(2200/3000) \* 3.73 === 2.74

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**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\
**Post date:** [August 29, 2022, 8:20pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/4 "2022-08-29T20:20:12Z")

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I believe its 2.73 for a chevy

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**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\
**Post date:** [August 29, 2022, 8:49pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/5 "2022-08-29T20:49:21Z")

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Anybody guessing OP is an auto shop class student? … lol …

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**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\
**Post date:** [August 30, 2022, 4:34am UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/6 "2022-08-30T04:34:27Z")

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> [@George\_San\_Jose1](#):
>
> Anybody guessing OP is an auto shop class student?

Classic cars like this are generally out of reach for teenagers. Since it has been modified for the drag strip, it is probably not a low-dollar clunker.

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**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\
**Post date:** [September 2, 2022, 9:43pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/7 "2022-09-02T21:43:19Z")

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If the car is equipped with a 2-speed Powerglide automatic or even a 3 speed Hydramatic, a 2.73 is going to make it dog slow off the line.

You could put a 200R4 or a 700R4 4 speed automatic with overdrive in it. Or if it is a 3 or 4 speed manual, a 5 speed Tremec TKX.

> [@Nevada\_545](#):
>
> Since it has been modified for the drag strip

Where do you see that?

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [September 3, 2022, 2:04pm UTC](https://community.cartalk.com/t/1970-chevrolet-malibu-classic-gear-ratio-help/186097/8 "2022-09-03T14:04:22Z")

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I changed a rear axle in a 70s Camaro from a 3:42 to a 2:56 and it brought the RPMs down to that range.