It is. Here we have a case where a guy wants to bump up power from a stock engine.
Unless there have been dozens of engine builders modding this particular engine and publishing known timing numbers, you have to come up with a plan on your own and doing it for as few dollars as possible virtually dictates you study it for a while before getting the die grinder out.
Given that its for aircraft use you don't want to go crazy with timing and huge ports. You can do a lot of experimenting and ruin cylinders and so on,where studying the engine and mapping the ports and developing a plan you can make an increase in power wisely without ruining anything.