I say find a Mercedez board (if you havent already) and find some people who have done what your thinking about doing and ask some questions to try and learn from their mistakes (if any) and their setups. Here are somethings to think about. How much boost are you gonna run? If you want to run only 2psi more then maybe you dont need to go through an engine buildup. What are the limitations of the stock engine and your current fuel system? If its bullet proof (like the Supra 2jz-gte) then you can run gobs of power before having to strengthen her. Will the Tranny be up to the increased Hp? What about tuning? Just a few things to think about. Hope I helped some.