Even at 84.5mm you'd need to bore the cylinders because the stock b20 bore is 84mm. If you are going to tear your block down, wait until you can get a nice set of forged rods and pistons. Forged rods will be much better at handling the high rpm of b20vtec than the OEM b20 rods. As for the higher compression and b20 cylinder wall stuff, I have seen what people have posted about the sleeves cracking with high compression pistons. However, this is a tuning problem. If you're going to go high compression, get a tunable EMS like the AEM or hondata...that's the way to do it safely and not detonate and cause damage.