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Transmission Ratio Drop From Gear to Gear

Sometimes selecting a transmission comes down to the drop between gears. This chart will show the percentage drop for 8 of GM's popular transmissions. The first column of each transmission shows the ratio for that particular gear while the second column of each transmission shows the percentage of drop for that gear from the previous.

Manual Transmissions - 4-speed
M20 (64-65) Percentage Drop M20 66> Percentage Drop M21/M22
2.56     2.52     2.20  
1.91 25.39%   1.88 25.40%   1.64 25.45%
1.48 22.51%   1.46 22.64%   1.28 21.95%
1.00 32.43%   1.00 31.51%   1.00 21.88%
               
Automatic Transmission - 2-speed, 3-speed
Powerglide Percentage Drop   TH350 Percentage Drop   TH400 Percentage Drop
1.76     2.52     2.48  
1.00 43.18%   1.52 39.68%   1.48 40.32%
      1.00 34.21%   1.00 32.43%
               
Automatic Transmission - 3-speed with overdrive
200-4R Percentage Drop   700-R4 Percentage Drop   4L80E  
2.74     3.06     2.48  
1.57 42.70%   1.63 46.73%   1.48 40.32%
1.00 36.31%   1.00 38.63%   1.00 32.43%
0.67 33.00%   0.70 30.00%   0.75 25.00%
               

Ground Up Chevelle Parts    Chevelle Transmission | El Camino Transmission