The dreaded Chevette rear end gear ratio subject !
For years and years, the subject of Chevette rear end gear ratios seems to constantly come up. I'm always kind of baffled by this, because whatever car you're dealing with, your going to have to "check" anyway to see what's in the car, rather than ask someone else what they "think" is installed. Plus, after all these years, there is always the possibility that the gears or rear end has been changed anyway. So the build sheet, or any other "evidence" may not mean anything. Pull the cover, or "roll the car".
Here is some good information provided by Mr. Fields:
The information below comes directly from General Motors.
Chevette Rear Axle Specifications:
Ring Gear Diameter: 6.5"
Pinion Shaft Offset: 1.125"
Ring And Pinion Ratios Available For The Chevrolet Chevette: (3.36:1) (3.62:1) (3.70:1) (4.11:1)
1976 - 3.70:1 Except 4.11:1 w/1.6 Liter Engine
1977 - 3.70:1 Except 4.11:1 w/1.4 Liter Engine, Or Automatic Transmission
1978 - 3.70:1
1979 - 3.70:1
1980 - 3.70:1
1981 - 3.70:1 Except 3.36:1 (Scooter)
1982 - 3.36:1
1983 - 3.36:1
1984 - 3.36:1 Or 3.62:1
1985 - 3.36:1 Or 3.62:1
1986 - 3.36:1
1987 - 3.36:1
The 4.11:1 ratio was an option in 1978, and was dropped in 1979.
You can also find some further information about this subject here, on the Diesel rear end gear page, which I highly recommend ! It's not just about Diesels.