300tdi transfer box swap

Im going to change the transfer box on the defender 300tdi . I was wondering what transfer box would be best to put in ? The discovery 1.22 box is what everyone seems to talk about . Would this be a straight forward fit to the 300tdi ?

I can sit at 55mph on a motorway and stress it at 60 but I’m hoping I can sit comfortably at 70mph with the 1.22 transfer box in ?

Is this achievable ?

I've a disco transfer box in my 110, it certainly will sit at 70 all day long. However I've also added a lot of sound insulation which helps a lot for comfort..

TheQ said:

I've a disco transfer box in my 110, it certainly will sit at 70 all day long. However I've also added a lot of sound insulation which helps a lot for comfort..

Click to expand...

Ahh great is that the 1.22 box ? with mine being the 300tdi do I need a transfer box from another 300 or I’ll a td5 or 200tdi one fit?

That sadly I can't answer an entire 200tdi and box was transferred into my 110 as I had a 2.5n/a before.

I fitted a 1.2 disco box to my 1989 90 (it had a 200tdi fitted to it) and all I had to do was tap 2 holes for the handbrake cable. Other than that it was a direct fit and definitely worth it. I wouldn't be doing 70 in a Defender no matter what but it is much better for cruising at higher speeds

Had my 300TDi 90 fitted with the Disco (1.2) 'box from new and it was always a fantastic conversion. Always run on 265/75x16s and it was the perfect combination.
Had to fit a 1.4 a few years ago when I swopped out to auto (the auto final drive ratio is a bit higher and it wouldn't rev out in top), I did run it for 12-months with the 1.2 but it just didn't work so had to get a 1.4 (from Ashcrofts who also supplied the auto kit). Now the gearing is spot on again.