EG's big bore takes the 200 to 225, and that isn't a sleeve.
He DOES make required changes to the main flapper....I don't know what that process is.
What about your head? If you don't change the oem head volume along with the bigger bore, you're going to have a self-destructing machine on your hands.
From other posts of yours, I'm sure you know that.....so I'm stating an obvious point I'm sure. Rather safe that sorry . ;)
From what EG says his big bore process is, I understand him to do SOMEthing with it....again......don't know what/how.
Does langcourt 'fix' the port timing with the overbore? Hope so.
Let us all know how it comes out! 2mm give you less than a 220 piston spec, so what piston are you using? Is it coming from langcourt, too? Hopefully they have the piston they're matching your bore to??
Good luck!!