Boring stock cast iron cylinders ?

[porschetub]

Can stock cast iron cylinders be bored (correctly) for larger pistons ,if so what is the max size,was hoping 86mm for my 2.2t.
I understand the correct machining procedure and know a company in my town that could do it,by the way labour charges in my country are some what low.
This is further my thread on JE pistons for cast cylinders,got screwed around on a recent purchase of a 3.0 so thinking about improving on my current motor,thanks in advance