HMF has dyno pulls on the webiste for what they make, i know fmf does as well, but they say something like 32 hp stock for a rappy 350, so i wouldn't trust anything they say.
All those results really arent worth a ******* crap you are wasting your time man. EVERY bike is dif and you will never ever get the same results as someone else unless everything is identical.
Same thing bro two stock motors are never identical and can produce different HP numbers - air temp, jetting, air flow, quality of fuel, oil, & a million other things effect HP results as well. Your best bet is to go buy quality of the pipe, reputation, and the assumption of 2-4 HP (depending on the pipe) as DSW said above.