I dont think anyone here would doubt a stock saw can easily see 30 to 40% gains with an aggressive muffler mod, proper tune and "razor" sharp square filed chain.
I know i wont deny that a stock say with factory round ground or hacked up roundground chain can easily see this nu.ber of improvement. Its not crazy priced. If this is hand touched square chain your talking $35 loop for stihl chain right well cheaper if he starts with square. And then the time to muffler mod and the $ 6 or so shipping. This is not really highway robbery. But it also is not a porting.