As Nash has said really mate.

its highly possible that its a 400bhp engine.

but i would be cautious with the turbo.
personal prefference would say the BD10s will go in the bin.
spacer plate on inlet manifold wouldnt be needed at that power level and would possibly give a worst throttle response having it in there.
unsure why it would need a converted 4x4 wiring loom, especially when its still running a L6.
and a bmw throttle housing - why?