The SVT Zetec is not a simple drop-in.
It mates to a 6 speed trans and not the MTX-75.
It uses a different ECU.
The mount points, engine mounts, trans mounts, brackets, and frame rails are all different.
Like any other Focus part, you could make some parts work, but it would take some work.
Getting a larger TB (whether aftermarket or from an SVT) isn't necessary unless you're doing FI, simply have the stock one optimized.
The head and intake manifold are the two points of interest.
If a complete SVT Zetec head can be found for real cheap (less than $500) it may be worth it, otherwise better cams and a PnP of the stock head is just as good.
The intake manifold is a dual runner design, like the 2.5L Contour. Which gives good both low and high end power. Something lacking in the design of any intake manifold currently available for the Zetec. But it's not even close to a direct fit and a way would need to be found to control it and have the ECU correct for the swap over between runners. It would take alot of time/money.
