Keep in mind that throwing a few parts at it won't make the gains the same parts can make with the right supporting parts.
For example, take a completely stock bike and replace only the head with a RE +1 head and you might only gain 1-2 hp
Now make it a 13-1 480, add a web 208, 43.5mm fcr, Dasa exhaust, and dasa intake but dyno it with the stock head, then swap out to the RE head and the head will bump the numbers by about 10 hp.
As for the dyno numbers I would also guess around 40, but as hoser said it's just numbers, they mean nothing unless you plan to go back after more mods to see what your gains are. If you plan to go back after more mods do yourself a favor and have a pre dyno routine, like fresh oil, clean filter, check valves, and clean and lube the chain, I have seen a non o ring chain that was dry gain 5 hp with a good shot of lube