I wanna change out my rear gear ratio. I believe i have 2.77 on my 89 formula. I want quicker accleration, but i also have to drive the car about 400miles a week so i need decent gas milege. I was thinking 3.08 or maybe 3.42, (I think that was it.) Let me know what you guys think. I drive alot on interstates at 80 to 85 so what would be best for me. Also is that a job i could do myself, any special tools required? Thanks Jimmy

 

If you have the 9-bolt 2.77, then your only choices are GM 3.27, GM 3.45, or aftermarket 3.70. And they're expensive.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

I have the original rear on the car, so what ever that is. About how much would a gear set cost? Which would you go with, the 3.27 or 3.45? How easy is it to install?

 

Do you have dual-cats or single cat? Single cat is 2.77, and dual is 3.27. If you have the 2.77 you're pretty much stuck with getting a whole new rear end. If you have the 3.27 you can pretty much keep it.

 

I would go with 3.27 if you do a lot of driving. I have 3.42 and get about 22 mpg on the highway.

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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

 

I would go with 3.27 if you do a lot of freeway driving. I have 3.42 and get about 22 mpg on the highway.

------------------
TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

 

I have a single cat under my car. Does that mean i cant buy a 3.27gm gear set and install it in my current rear end? Im kinda confused on this.