Are 3.73's too big for a 305TBI/Auto?
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Joined: Jun 2004
Posts: 647
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From: South Jersey
Car: 1991 RS Convertible
Engine: 96 LT1
Transmission: T5
Axle/Gears: 3.45 9-Bolt
Are 3.73's too big for a 305TBI/Auto?
I am about to get a new rear for my car. I am upgrading from a 2.73 open diff w/ drum brakes.
I want to know if I should go with 3.73's or 3.42's. The car is driven on the highway from time to time. I hit 80+ mph once a week. What kinda crusing RPM's will I see with both gears?
Thanks in Advance,
Mark B
I want to know if I should go with 3.73's or 3.42's. The car is driven on the highway from time to time. I hit 80+ mph once a week. What kinda crusing RPM's will I see with both gears?
Thanks in Advance,
Mark B
Joined: Feb 2001
Posts: 13,756
Likes: 560
From: Cincinnati, OH
Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
Use the calculations page to determine RPM. I would go with 3.42's. 3.73's are a tad steep for a stock 305 TBI. You don't want to get to far out of your powerband to fast. It is hard to beat the versatilty of the 3.42 gear.
Joined: Jul 2000
Posts: 6,521
Likes: 91
From: Aridzona
Car: `86 SS / `87 SS
Engine: L69 w/ TPI on top / 305 4bbl
Transmission: `95 T56 \ `88 200-4R
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