I was wondering how hard it is to build your engine yourself, meaning taking it apart and putting in forged internals and such. I would like to build my motor up to handle over 500rwhp. Is it something I can do or would you recommend having a mechanic do it. Can it be done with the motor in the car? Also, my motor has 112,xxx miles on it. Would it be worth building up or not? Any information or advice would be great. Also, do the kits come with detailed instructions?