Gear ratio
Thread Starter
Burning Brakes
Joined: Jun 2002
Posts: 1,159
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From: royal palm beach florida
Gear ratio
I am trying to find out if I HAVE A 307 GEAR RATIO. i HAVE A 94 AUTO WITH 31517 35 tires on ,at 80mph the tach reads 2000rpm.any help would be appreciated. 
Safety Car
Joined: Apr 2003
Posts: 3,793
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From: VA
I think the only factory gears on an AT in 94 are 2.59 and 3.07.
2.59 is probably within the error of the speedo and tach for the numbers he gives.
The RPO doesn't help, but if you look on the diff itself, the ratio is engraved on it. Or test the number of rotations manually.
Well, actually the RPO will help a little. It will tell if it is 2.59 or "not 2.59"
2.59 is probably within the error of the speedo and tach for the numbers he gives.
The RPO doesn't help, but if you look on the diff itself, the ratio is engraved on it. Or test the number of rotations manually.
Well, actually the RPO will help a little. It will tell if it is 2.59 or "not 2.59"
Last edited by VenkmanP; Jun 13, 2011 at 09:35 PM.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by steve9899
The RPO doesn't help, but if you look on the diff itself, the ratio is engraved on it. Or test the number of rotations manually.
Well, actually the RPO will help a little. It will tell if it is 2.59 or "not 2.59"
Well, actually the RPO will help a little. It will tell if it is 2.59 or "not 2.59"
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Safety Car
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From: VA
Originally Posted by CFI-EFI
The RPO number WILL tell the ratio. If it is the standard ratio for that exact car, year, engine, transmission, and body style the "G" RPO number will be the rear end ratio. IF the car has the "performance ratio" for that exact vehicle, there will be 2 different RPO numbers starting with "G". One will be "G92" which designates that the car has the "performance option" and the other will be the code for that specific ratio. If you find a "G92" keep looking for the other "G" number. THAT is the ratio designator.
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Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by steve9899
I thought that we've had quite a few people post who had G92 but no ratio designator. Can't find any in the limited search available though...
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Melting Slicks
Joined: Mar 2005
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From: Northeast FL
Originally Posted by CFI-EFI
The RPO number WILL tell the ratio. If it is the standard ratio for that exact car, year, engine, transmission, and body style the "G" RPO number will be the rear end ratio. IF the car has the "performance ratio" for that exact vehicle, there will be 2 different RPO numbers starting with "G". One will be "G92" which designates that the car has the "performance option" and the other will be the code for that specific ratio. If you find a "G92" keep looking for the other "G" number. THAT is the ratio designator.
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but only if you can confirm the gear hasn't been changed from stock.
Drifting
Joined: Feb 2004
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From: Santa Maria CA
Originally Posted by ed petrucci
gear ratio 101. i have a 3.07 rear end in my 86, whats that better for, off the line or high way speeds and top end?
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From: Athens AL
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Originally Posted by ed petrucci
gear ratio 101. i have a 3.07 rear end in my 86, whats that better for, off the line or high way speeds and top end?
Powerband comes on so quick that its not necessary to have lower, and is so short that its not really at all useful to have higher.
