You'd have to change out everything else too if you're " just trying to bring the car up to the 21st century"
Anti lock brakes , traction control, VVT, VCT, and some sort of driver assistant watching how you interact with traffic, park, merge, and drive. Lastly, you'd have more than a 5 gear manual trans...in favor of a much faster, and more efficient dual clutch 7/8/9 gear automatic. ( even BMW IS no longer manufacturing a car in the mainstream line where a manual is available..only the "M" cars get one,...but it a standard feature,....if you want speed and efficiency, you let your ECU control the shift, and you pay 2700.00 more dollars to get a DCT.