Package pricing and technical notes below
Early Broncos 66-77 came with a 3 speed manual trans, column shifted. A C4 3 speed automatic also became available 73-77. (If you are wanting to add overdrive, however prefer to use an automatic, we offer packages to use the Ford AOD transmission and the GM 700R4)
If you prefer a stick transmission, and want a 5 speed, The choices are Ford ZF 5 speed, NV4500 5 speed and NV3550 5 speed. The ZF 5 speed is available to bolt in behind the Ford 302 or 351 Windsor, and we carry an adapter to mate this to the Bronco 20 case. The Dodge NV4500 is generally considered a better transmission than the ZF. We also carry a package developed to install this transmission in the Early Bronco. Both of these transmissions are truck type trannies. They have deep 1st gears which are useful in hard core offroad. An they also shift like a truck
The NV3550 trans is a medium duty trans originally developed for use in Jeeps. It will comfortably handle the power of a medium power V8. They shift smoothly with a light feel. The weight of this unit is 97 lbs. Size and weight, it is a likely replacement for the stock trans. All in all, a very good candidate for a transmission upgrade in an Early Bronco. A Conversion to the NV3550 might be just what the doctor ordered.
We can supply the NV3550. We have also put together a package of the key items needed to make this upgrade.
Below are technical notes on what is involved.
Conversion Package shown below
Parts can be purchased separately.
The package is designed to work in conjunction with the stock Ford flywheel, bellhousing and clutch linkage.
(We can also provide custom packages where needed)
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Below is what is involved in a conversion:
A minimal body lift or minimal floor pan support modification is required to install this transmission.
If you are converting from an Automatic the below clutch components will be needed
Clutch
Your stock pressure plate and Throw-out bearing will work, however should be replaced if not known to be fresh. We can also supply these parts as a part of your package (Package pricing tends to be better than prices for items purchased separately)
Transfer Case
The Early Bronco came with a version of the Dana 20 that was specific to the Early bronco: It has a front driveshaft on the driver side. The package is available with the necessary adapter to retain this stock transfer case
Other options include an Atlas Transfer Case.
Crossmember
The stock crossmember will not work. We offer a replacement crossmember as a part of the package
Driveshafts
The NV3550 with the necessary adapters installed is 26″ long from rear of bellhousing to front of the stock Tcase. You may measure your current transmission and adapter combo and compare these numbers to determine if driveshaft modification will be necessary.