Don't ask how I know... just be glad I know...Your best bet for a Focus would be to buy a junked Contour with a 2.5L (regular or SVT) with a spun bearing or something, to snag the heads, manifolds, and accessories off of. Then, buy a prepped 3L from
http://www.buckshotmotorsports.com since you haven't been around the 3L forums long enough to have absorbed all of the information needed to complete the modifications to the block. If you stick around long enough though, you can search into the archives and find most of the info you would need.
As far as the mounts and such... you need the Contour trans mount with the Focus top half to attach to the frame. The upper passenger's side mount (and power steering mount) needs the Contour pieces if I remember... The roll restictors may need a custom mount fabricated to attach to your Focus sub frame.
The Focus trans has a different mounting flange and won't fit. Use the Contour's MTX75 and Focus shifter tower if they are different. You can have a trans shop swap over the Zetec final drive because the lower Contour gears (higher numerically) added to the extra torque of the 3L will just spin your tires. The longer legs of the Zetec final drive would match your ligher weight perfect. Might I also suggest a Quaife diff for some amount of control.
Custom axles with Focus outer shafts and Contour inner shafts will be needed. The Contour passenger's side support bearing will be needed also.
Contour engine wiring harness will be needed, along with the ECU and a custom chip. If your car has a tach that you want to work, grab a Cougar cabin wiring harness and gauge cluster. There will be some customizing to make everything work, but as long as you get the wiring diagrams from both cars you shouldn't have a problem. The gauge cluster is a bolt in for the Focus after the wiring.
I also suggest true duals in a 2" or 2.25" if you do headers and P&P heads or something. Single 3" loses to much velocity and just sounds really crappy. Believe me, I know... I had over $600 of 3" stainless exhaust sitting in my garage rafters for over a year because I couldn't get it to sound good with
ANY muffler/s on my 3L Contour SE.
Final note: SVT parts are expensive for the most part and not entirely needed. The SVT hybrids typically put out 10-15 more HP/TQ than the SE hybrids do. Weigh that into your cost scale to determine if it's worth it for your car.
