if you fit 300 in proper place you will need more parts but they will all be standard ,like exhaust ,disco and def front pipe are the same ,disco front prop same as def 300 ,pas box etc same ,rad intercooler the same but needs 2 x locating studs removing from bracket and fastening direct to lower frame and both side brackets removing ,you would need to source rear prop ,tunnel,floorplates etc gearbox crossmember bolts into def with original def mount holes needs some metal removing from seat box support,300tdi and v8 gearbox fit in same place which is about 2 inches further forward than 200tdi and 2.5s ido know someone with 300 tdi auto gearbox it would fit the same as manual r380 ,disco r380 i change to def spec by swapping selector shaft and fitting def gear change housing lt77 one can be used, i would be willing to show you how