Gear ratio on a posi

Old October 24th, 2018, 08:52 AM
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Gear ratio on a posi

I obviously own an 84 Oldsmobile Delta 88, itís got a 307 with a 4 speed auto, and a posi rear end. I was attempting to do some research but I guess my car isnít really common or something, so I couldnít find anything in the rear differential gear ratio. I found the transmission ratios but no differential ratios. Any help would help me
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Old October 24th, 2018, 09:34 AM
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Does that year vehicle have an RPO sticker somewhere, such as in the trunk? If so, it should have that info.
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Old October 24th, 2018, 09:34 AM
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Count the number of tire revolutions to drive shaft revolutions. That will get you in the ball park. Pull the cover and look at the ratio stamped into the ring gear. Probably could use a rear gear service any how. Likely a high 2 or low 3 series.
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Old November 18th, 2018, 04:42 AM
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According to the 1984 Dealer album, 2.73's were the standard gear set for the Delta 88 with the 307 V8 and 4-speed overdrive transmission. 3.08's and 3.23's were optional (with the HD cooling) except in California. High altitude cars got 3.23's standard. As Fun71 said, there should be an RPO sticker (most likely in the trunk on the lid) with all of the codes on it.
GU2 = 2.73
GU4 = 3.08
GU5 = 3.23
G80 = limited slip (posi)
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Old November 18th, 2018, 11:05 AM
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Just looked at it has two codes on it, GU2 and G80. So I’m assuming that it has 2.73 gears and limited slip right? I know for a fact it’s posi though
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Old November 18th, 2018, 11:15 AM
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Yes, correct. It is a 2.73 posi.
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Old November 18th, 2018, 11:18 AM
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Got it thanks for the help!
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