I will be rebuilding my topend soon. I am pretty sure that I will get all my stuff from CWR... as they are the cheapest, and the best, lol. I am gunna get the cwr 335 kit that includes piston,sleeve,gaskets. Do you think I will need to run race fuel in there? or would premium unleaded be good? And I have heard that once you bore it out, it's not very reliable. is it true?
Heres their website...

I'm guessing if you romove metal, then your remove some of your ability to dissipate heat. This will make the engine run a little hotter. Also if you have a new big bore sleeve put in then they must remove aluminum as they must bore a bigger hole through the cylinder to make room for the bigger sleeve. So inevitably less metal, and now your also producing even more heat from the extra cc's. To compensate, I'd just spend a little more on a better quality oil and change it twice as often as you would have normally. And for the gas I think that you would be fine with any premium grade fuel from your local petrol station. It would be nice if a manufacturer could make some sort of extra capacity cooling systems to go with their extra capacity engine kits. Maybe there's an aftermarket oil-cooler for your Lakota.