Re: Stock horsepower: raptor and 400ex?
If you plan to run +5 on the stock axle you'd better plan to replace the broken or at least bent stock axle. According some knowledgible people the proto type Raptor had a wider axle and had a nunber of failures, so instead of using a stronger axle they simply shortened the original axle to reduce the stress to an acceptible level.. Also in running that wide an axle you'd likely require wider A-arms to correct the steering/handling geometry.
After bending my OEM axle, I 'm now running a Lone Star axcaliber +one. The handling in corners is greatly improved , requiring much less weight transfer. Also it still allows me to ride tight trail & woods .
Oh, and btw, every test of the 400ex that I've read showed the H.P. rating at between 26 & 28 depending on whose dyno was being used.