Hello!!!

I am looking to change my 3.9 V8 and instead of that, put a 300TDi. Do I need to change also the Gearbox? Are there any other major changes that I also need to do? Is it easy?

 

You will need the ECU, mod your fuel system, install a intercooler, change your exhaust and a few other things I am not thinking of.
As long as it is a Rover diesel it will bolt right up to the transmission.
Double check that you dont need a TDI bell housing, but I am 99% sure you can use yours.

 

Rovers from the factory have a different gearing in both the tranny and t/case. If you use the stock tranny and t/case, if you still need to look at gearing, then go to your diffs.