Did gasgas changed valve stem diameter over years?

[Ignas]

I have ordered new valve guides for my fse 450 and got wrong ones. They are for 4mm valve stem and i have 5mm valves. Outside guide diameter is 10.55mm and mine are 11.35
Did Gas Gas changed valve stem size at any year?

I have measured all 4 guides and it turns out that i got one guide with 4mm and three with 5mm inside diameter.
Is there any difference between MFS400116046 and MFS400116046R parts?