Be careful about over doing it if turboing R5 renaults 1.4litre pushrod engines made 400 plus hp and killer torque but had plenty of meat on the walls to allow 50psi.
We are lucky enough to have 1500cc A engines but Ive lost 2 1607cc A15 na motors thanks to cracks in the walls.
Better be safe and use the latest turbos like nissans variable turbo designs instead of the older designs these new turbos make awesome torque from down low and all the way through to redline the article of this new technology variable turbos is in a recent zoom mag and sorry to not be clearer is just that I never planned to turbo an engine.
Phunk what force induction were you going turbo or Supercharging I forgot....

end result looks like this with exception to the o-rings

If one is going after the bigger bores, it might pay to offset them a little to avoid an excessively thin gap between 1 & 2, along with 3 & 4. Measure thrice, bore once.

My pic is of Standard A15 bores, but if you were to offset them, how would you compensate for this, on the crank, rods or pistons

The wrist pins run fore & aft & there should be enough movement available to accomodate. I'm not talking 1/8" here as we must also think of wall thickness. Sometimes just a few thou can help.

If one is boring one oversize up, then keeping the cut on the side closest to the adjoining cylinder to a minimum will mean the smallest amount lost in the deck between them. There isn't a lot of meat here, & blown engines make a lot of combustion pressure, so keeping the sealing surface as large as reasonably possible in a heavily overbored engine [like my 1200] will help gasket life.
Do a lot of thinking, & measuring, before boring too far. I have seen an engine that needed figure 8 "O" rings around the bores because there was not enough meat between them for two full circle rings.

Quote:
Was it the pick below.
Its not that good of a pic to see this but if you look at cylinders 3 and 4 you should be able to make out that it is a figure 8 and not 2 o-rings