Chainsaw Repair

Hey guys and gals. Easy one here. I know you can buy something, a kit or something that will allow you to get more cc's or cutting power from your chainsaw. It has something to do with the governor built into most saws. First what is this called? What saws are better to do this with? How much of a difference are you looking at? I read a story online that I cannot find right now anywhere that a airbornest guy had two identical saws and had one that he used done this way and the other he let his crew use that wasn't done this way. He said although neither had gone down or overheated as most people say they will. The one he "pegged out" was 20% faster and only needed to be sharpened more often which led to going through chains only slightly more than the other saw that was all stock. I think if your turning more rpms then yes your gonna need to replace the chain sooner. His point was that doing this from his everyday usage only cost him about 10% more in cost but makes his jobs much faster which offsets that cost.
Since I am looking to get a saw to replace my hsk 256 I was thinking of staying with a saw where this is possible to do whether I do it or not. I just can't remember what it is called. I know he said not all saws could or should be done like this. I am either gonna go with a Husky or Jonsered so I wanted to know before I went any further.

Thanks

Big bore kit? Gets more cc's but not an oem option in most cases.