Welcome to PassionFord

Its a bit hard to answer your question...I think you mean you have a ahmed chip to run greys but you are unsure what else you need to go with this to get 400bhp??

If so, then I would say proberbly a hybrid T35....a pair of BD10 camshafts...and a good solid standard bottom end. Not sure on what octane the fuel is in your country tho?? So dont know what to say regarding compression ratio....

On top of this you would need to get it set up properly on either a rolling road or more idealy a live mapping session.

Hope that helps..

Stu