Jim Smart
March 1, 2009
Here, we have four gears. On top is Second gear in 28-tooth (left) and 31-tooth (right), the latter being wide-ratio. On the bottom is a pair of Third gears, both 25-tooth, which applies to close- and wide-ratio.

Close vs. Wide Ratio
Which Top Loader transmission should you chose, close or wide ratio, and why? Close-ratio is centered mostly around quick acceleration, which is why you'll find them in the Boss 302, Shelbys, and other high-performance applications. Wide-ratio makes more sense for open-road driving.

Wide-ratio is the most common Top Loader. Gear ratios stack up like this:
First Gear:2.78:1
Second Gear:1.93:1
Third Gear:1.36:1
Fourth Gear:1.00:1 (Straight Drive)
Close-ratio stacks up like this:
First Gear:2.32:1
Second Gear:1.69:1
Third Gear:1.29:1
Fourth Gear:1.00:1 (Straight Drive)

Gear ratio boils down to how many revolutions the input shaft turns versus how many revolutions the output shaft turns in a specific gear. For example, if we have a First-gear ratio of 2.78:1 in a wide-ratio box, that means the input shaft turns 2.78 revolutions for every one revolution of the output shaft.

How do you identify close- or wide-ratio? Although we want to trust the identification tag, that's not always possible because many of these older transmissions have been rebuilt in the past. In some cases, close-ratio transmissions have been converted to wide-ratio and vice versa. In fact, we're taking a wide-ratio box and turning it into close-ratio for racing purposes. When you want to be certain, pop the top cover and count the gear teeth.

Wide-Ratio looks like this: GearCluster Gear
First Gear:32 Teeth15
Second Gear:31 Teeth21
Third Gear:25 Teeth24
Fourth Gear:23 Teeth30
Close Ratio looks like this:
First Gear:32 Teeth15
Second Gear:28 Teeth18
Third Gear:25 Teeth21
Fourth Gear:23 Teeth25