Tech article by Jon Hanna (Admin)
Manual Trans Intro
See also: Automatics

Toploader (also called "T&C" or "10 bolt top cover") 4 speed manual
1967-1982 Ford cars and some trucks. Since it was used for so many years there are several different versions of this transmission. Tail shaft lengths will vary, but you won't need the tail shaft anyway, just the case.
As the name implies, this transmission has a 10 bolt top cover to the case, rather than the more usual side cover plate. The case itself is 10.25" with a side mounted, external style shifter. These came in both "close ratio" and the more common (and more desirable for Broncos) "wide ratio" versions. Look at the tooth count on second gear. A "close ratio" will have 28 teeth and a "wide ratio" will have 31 teeth.
Adapter required?
The "adapter" needed in this case is an aftermarket output shaft, along with a shifter bracket and rod kit. The Toploader case takes the place of the stock Bronco transmission, so no adapters are needed to correct the bolt pattern. The stock Bronco 8 cylinder intermediate housing is retained, although modified (see below)
The Toploader is a fully synchronized, quick shifting and strong transmission. Because they came in so many vehicles they should be easy to find. However, they're also a popular choice for several swaps including the Mustang and Jeep crowd, so demand may inflate pricing for both parts and transmissions.
Gearing is even higher than a stock 3 speed, which can be a pro or con, depending on how you drive. The high 1st gear is not typically ideal for the trail, especially rock crawling. However, if you spend most of your time on the highway the gearing may be exactly what you want. The closer shift points are also an improvement over the stock 3 speed. Since the shifter rods are on the side they can be vulnerable to getting jammed with mud and snow. An alternate top shifter came on some truck transmissions and replaces the top cover with one that has the shift forks built in.
Cost: (Approximate)
Transmission: $400 used and $750-1000 rebuilt
Adapter (output shaft): $250-350
Shifter $250
Bell housing:
Standard Ford. The Toploader will bolt up to your existing bell housing on small block (289-302-351) engines. The existing Bronco clutch is also used.
Modifications needed:
The entire assembly is 1" longer than a stock 8 cyl Bronco transmission, so drive shaft modifications may be necessary depending on the amount of suspension lift you have. The stock Bronco 8 cylinder intermediate housing needs to be machined for the larger Toploader bearing and drilled to accept the shift rail. You'll also need to cut a hole in the floor for the side shifter. A four speed floor shifter needs to be installed, requiring some floor board cutting.

Manual Transmission Gear Ratios1st2nd3rd4th5th
Bronco 3 spd (6 cyl)3.411.861.00
Bronco 3 spd (8 cyl)2.991.751.00
NP 4356.693.341.791.00
Toploader (Close ratio)2.321.691.291.00
Toploader (Wide ratio)2.781.931.351.00
Toploader (Overdrive)3.291.841.000.81
NV4500 (Dodge)5.613.041.671.000.73

Automatic Transmission Gear Ratios1st2nd3rd4th5th
Bronco C42.461.461.00
AOD w/ low gear set2.841.551.00.67