A couple of suggestions

[nialloftara]

The question for over/underbore though so valve placement doesn't apply, and as for compression it only had 6.48:1 anyway.

[wplxs8]

Back to the core question, perhaps?

As I witnessed myself: it is possible to widen a bore, if the block allows it, to a certain amount. We did widen a 1800 gti mk1 engine to 1900cc in one of our RX-cars. And you can elongate the stroke by using longer conrods and thinner (but better) pistons.

This techniques to secretly raise the capycity just a little bit are considered a bit shady in motorsports but not uncommon.

So to raise and/or lower both bore and stroke is technically possible in the real world (alas lowering the stroke should reduce reliability, since the sleeves react to heat differently as the block itself)