I dunno, my first gear is still pretty sluggish...lol\
I put a non turbo in mine, I kept my stock radiator (not realizing they were different) and its been fine so far, kept my original rear end. Used my original aluminum mount arms. The valve cover holes are in the same relative location to the mounting points of the engine so the original throttle parts can be reused. I also reused the origional engine oil cooler and lines.

What I had to change to make the swap:
1. trans cooler steel hard lines are longer on the 5 cyl.
2. trans shifter linkage rod under the car is shorter for the 5 cyl.
3. trans crossmember is different, uses the next back set of body holes (and the drive tunnel is tapered so the 5 cyl member has a shorter span).
4. driveline front section is shorter, rear section is girthier for 5 cyl.
5. Had to add one wire and connector pin to my glow plug relay harness for the extra GP, to the pin labeled G5.
6. used the clutch fan that was with the 5 cyl (for better mileage/power), but the plastic origional non clutch fan would've worked.

Everything else is pretty straightforward. My mileage as of last week is right about 33 mpg.

__________________
Chris
64 190D R.I.P.
80 240D W/617 engine -for sale
82 240D -for sale