Hello dudes

Can anybody please confirm that the 1988 MC18 2J MK1 & the 1989 MC18 R5K MK2 steering stems are different lengths please ?

I realise that the mc18 MK1 & MK2 top yokes have very different vertical thicknesses where the steering stem passes through them and therefore i assume the yoke stem length must differ ?

Can anybody please tell me the length of an 1988 MK1 MC18 2J & a 1989 MK2 MC18 R5K bottom yoke stem in millimetres please ?

I have in my possession what I believe to be a 1988 MC18 2J MK1 bottom yoke, the steering stem is around 225mm long which is 10mm too short for my MC18 R5K top yoke & top lock nut.

PLEASE HELP !