Clutch wont disengage

Can't measure it but 5mm sounds about right and should be enough. I'll have a look at the diagrams of the clutch to see if I have any suggestions.

How did you try to see if it disengages? If the bike has been standing still for a while the cold oil makes the plates stick and it will feels like it doesn't disengage if you try to push it manually.
I know it's dangerous to try other wise but let the engine warm up then switch it off and try again with the oil warm.

i'd suggest, instead of starting it, put her in gear and rock the bike back and forth with clutch engaged. if the plates are stuck together, this will free them. if the cluch is really not dis-engaging, it will not...

is your engine out of the bike? if so, this is probably not very helpfull...5mm sounds ok though, and if all you changed is MC, i don't think there should be a problem there, apart from possible need for bleeding the air out.

Have bleed system 4 time to be double sure.final time i back bled it.

Engine has correct brandnew oil in it.

Have tried both things you guys suggested and still same.

Do you have verniers or micrometre to measure the plates and stack?
Not one plate too much in it.....?
Shaft centred properly? Never done it but I have been told the shaft can sit in a position where it doesn't push straight.