Thread: Diff Ratio's

Originally Posted by Tonestar

G'Day.............

I want to know where I might be able to find 3.9 Diff Ratio Gearing for my
"2A",as I want to change it from the 4.7 thats already in it which is standard.
OR if anyone has a better suggestion to get more speed out of it as I'm
converting it to a 253 V8.Maybe the diff centre out of a V8 Landrover
would do the job......would it fit.???????
Much Appreciated.

Tonestar.

Early Rangie 10 spline diffs 3.54 ratio will fit , no 3.9,ratio available that i know of

You could use Range Rover Classic diff centres but the ratio is 3.54:1
The rear diff in your vehicle is a bit light for its application so I would look
at a set of diffs from a Stage 1 V8 (also 3.54:1) this will include the rear Salisbury that will not have strength issues.
You could also put 60 Series Land Cruiser diffs in from memory I think they are 4.1:1

A lot more to it than just changing the ratios.

Rover 90 P4 cars of the 1950's had 4.3:1 diff ratios
Rover 3 litre P5 cars of the 1960's had 3.9:1 diff ratios
and everything was completely interchangeable with the (non-Salisbury or ENV) series Land Rover.

Finding them will be your problem.

I had a 253 (4.2 litre) powered Land Rover and you will find that the series box is not up to the task.

Why go to all the trouble with the conversion and engineering when you can buy an off the shelf County or Defender with a 3.5 or 3.9 litre engine and change it to a 4.6 if desired.

Diana

You can the following ratio's new from KAM Differentials for Rover type diffs.
Ratio overview

4.75, 4.2, 4.1, 3.8, 2.83.

4.11, 4.75 and 3.54 from Ashcroft Transmissions.

I thought that Great Basin Rovers had 4.1 and 3.9, though nothing has changed in the last few years and their website is still not properly functional.

4.7 from 4cyl and 6cyl series leaf sprung Landrovers, and 3.54 from every other front and rear beam axled LandRover.

I got my 4.7's from great basin rovers.. helpful & good service.

Jeff