hi could anyone tell me will a 1.8 td4 2000 plate IRD fit a 2litre diesel on a T plate 1998 ???

Hi lespingu, the IRD boxes are the same types for all the Freelanders except for the KV6 and North American Standard NAS. This is the part number: TAG000230.The ones from any 2000 model should fit your 1998 one, provided that the IRD didn't come from one of the very first KV6 Freelanders which commenced production in 2000.