300 tdi into Disco 2?

Hi, was talking to a friend of my wifes last night about her TD5 which she drove to destruction with a horse trailer behind after a hose split, lost all its coolant and she cooked it big time, i have'nt seen it myself but our local independent Land Rover specialist says its f**ked. Money isnt plentiful and a secondhand td5 lump still fetches quite big money so was discussing the idea of fitting a 300 tdi into it, i might be wrong and i know you'll all soon correct me, but the gearbox is the same right? What i really want to know is if anyone else has dropped a 300tdi lump into a Disco 2 as a TD5 replacement, and, how involved is it? Obviously the 300 doesnt need an ecu to run, or an electric fuel pump, but how easy is it to get round all this? And, what about engine mountings because the chassis is different? I mean anything is possible but would like to speak to someone that has done it, or is it really all too different to warrant the labour involved? Its a 2001 Y reg and quite a tidy truck so would be a good basis for the conversion. Any help will be greatly appreciated as i dont want to take the job on without a bit of insight first, look forward to some replies, many thanks.

gearbox while been an r380 wouldnt fit to 300 without changing bell housing and input shaft ,spigot brg is the same but length is different,the cost of fitting 300 would be far more than td5 £1000-1500 in theory u only need 12v feed to solenoid and a pipe to suck fuel from tank to run 300tdi