Before everyone else asks... 'Please post before & after dynos'.
Regarding being close to 300hp, their 250 kit states 253hp, so you'll be closer to 300 than 200 if that's what you're asking. Remember, if a product (say pulleys) frees up/gains you an extra 10hp on a stock engine, it will not gain you that same 10hp on a modified engine. An engine will only produce so much power - you're just extracting all you can.
Those last few horses are the most expensive ones!!!