Contact Info Price Match Search Email Us Home

                                                                                                        Call us at 888-316-2940



Transmission & Gear Page
High Impact Home


Stick Trans Info Pages:

Guide to 4WD Gearing
Customer Free Tech Line
Complete Conversion Kits
Klune-V Extreme Underdrive
NV4500 5spd
NV3550 5spd
Other Stick Transmissions
Overdrive Conversions
Overdrives & Underdrives
Contact High Impact
Apps by Vehicle Type


NV3550 Package info

NV3550 5spd replacing AX5
NV3550 Jeep/Peugeot Replacement
NV3550 into Early Bronco
NV3550 5spd Wrangler 4.0
NV3550 5spd replacing automatic
NV3550 5spd Wrangler GM V8
NV3550 5spd Wrangler Ford V8
NV3550 5spd Wrangler AMC V8
NV3550 CJ AMC eng Dana20
NV3550 CJ GM eng Dana300
NV3550 CJ GM Eng Dana 20



CJ with GM V8 & Dana 300: NV3550 5speed Conversion

NV3550 conversion

The NV3550 is an excellent option to consider in smallblock V8 Jeep applications. It will comfortably handle a mild V8 in a vehicle such a as a Jeep, and will fit under the body in a Jeep with very few additional modifications.

NV4500 Conversion

There is one other popular 5 speed option for the Jeep CJ: The NV4500. This trans is way-oversize for the application, and requires a body lift or extensive floor pan modification to fit. The usual incentive for this conversion is to get the truck style wide ratio, almost granny 1st gear which can be useful for offroad use. On the other hand, this conversion will make a your jeep drive more like a  truck. If this looks like the option or you, High impact does have available a package using the NV4500.  

NV3550 / Klune-V Extreme underdrive

Rather than a granny gear 4 or 5 speed, a more "premium" alternative to achieve extreme gearing would be an NV3550 combined with a Klune-V Extreme Underdrive.

NV3550 conversion Details

Conversion Package

High Impact has available a package providing you with all the primary essential ingredients to this installation. The NV3550 will fit under the stock body without a body lift. Only minor floor pan mods are needed where the shifter handle comes up.   

Adapting to the Transfer case

Jeep Dana 18 and Dana 20

Most Dana 18 or Dana 20 transfer cases can be bolted to the NV3550 through the use of a standard adapter (listed below in the kit detail)

The notable exceptions are: 

1969 - 1971 Jeeps with the T14 transmission used a 10 spline shaft. In this case, it is necessary to replace the original 10 spline input gear with the equivalent gear-tooth-count 6 spline version.

The 70's Jeeps with Turbo 400 automatics had a 32 spline output shaft and used a spud shaft in an adapter housing. The T-case input gear is carried on the spud shaft. This gear is not compatible with the six spline version: You must replace this input gear with the equivalent gear-tooth-count 6 spline version. 

Scout versions used with an automatic transmission: This gear will have a 23 spline configuration. It must be replaced with the Scout gear from the manual trans applications, which will have the correct 6 spline configuration.

Dana 300 - The Dana 300 was the standard transfer case supplied in CJ jeeps 1980-up. Note that the NV3550 tail is drilled to fit NV231. D300 will fit, however will be rotated down approximately 9 deg: To correct this, the NV3550 tailhousing will need to have 6 holes re-drilled. If desired, a rotation adapter plate kit s available to make this a bolt together.

Atlas II Transfer Case - This case is available in configurations for direct bolt up, and is a definite upgrade option over stock units.

Klune-V Extreme Underdrive - This unit is a premium option where extreme offroad gearing options are desired. The unit fits between the transmission and transfer case. The Klune can then be coupled to a transfer case such as the Dana 18 or Dana 20, or perhaps an Atlas. Due to the additional length when adding this unit, there are various issues that must be addressed to ensure proper driveshaft operation. Overall engine length, engine placement, transmission length and transfer case length must be considered. All this must fit behind the radiator and sufficiently i front of the ear axle to allow minimum driveshaft length. We have found that proper driveline geometry is allowed for, drive shafts as short as 11" will work well.  Link: Discussion on driveshaft geometry issues. Please call us if you are considering such a system and have concerns not covered in the website. 


Part can be purchased separately also.

(We can also provide custom packages where needed)

# NV3550 in Jeep w/ GM SB motor Priced Separately PkgPricing* Total


1 NV3550 Jeep 5spd 4WD Transmission $1,200.00 $1,200.00
Shift Handle: You will need to modify your existing shifter by cutting off the current end, and welding on a steel plate and drilling holes thru the steel plate to bolt up to the stub sticking out of the trans.    
Adapter / Installation kit - This kit supplies a complete new bellhousing and external slave cylinder and hose kit    
1 Bellhousing and pilot bearing kit (this BH is limited to the smaller 153 tooth GM Flywheel, unless high torque starter listed below is used) $335.42 $335.42
1 Slave cylinder $62.50 $62.50
1 Hydraulic Hose (to adapt new slave cyl to stock YJ Wrangler master cyl) $40.63 $40.63
1 Hydraulic Hose adapter (to adapt new slave cyl to "Iron Duke" style CJ master cylinder) $9.37 $9.37

Adapting to the Jeep Dana 300 transfer case

NV3550 to Dana 300: The Dana 300 will bolt up, however the bolt pattern rotation in the NV3550 will likely cause the D300 to hang excessively low. This can be corrected by using a gasket as a template and re-drilling the pattern in the adapter of the NV3550. If preferred a bolt on rotation adapter is available:    
Option: Dana 300 Rotation Adapter kit. (3/4" thick) $172.65 $0.00

Clutch components: A stock GM pressure plate and Throwout bearing may work. The high-top PP in conjunction with the N1714 T/O bearing listed are known to work with the slave cylinder being used. It is also  recommended you replace the clutch components unless they are known to be fresh

1 Throwout bearing $34.31 $34.31
1 Pressure Plate $167.89 $167.89
1 Clutch Disc $82.04 $82.04

Items you may need if you do not have the Correct flywheel for this conversion 

(The BH supplied in this kit is limited to the smaller 153 tooth GM Flywheel, unless high torque starter listed below is used

153T FW GM Smallblock $242.50 $0.00
High Torque Starter (Using this starter with NV3550 BH to GM engine will allow use of 168T FW) $235.00 $0.00
Slave cyl spacer kit - needed to fit high torque starter w 168T FW with this BH. NC