Kamil, I think you need to better explain the parts that you have available to you to get good answers here. Not everyone is following along with your recent acquisitions.

He is mixing parts from three cars in this conversion.

From what I have read here I think you have enough to do a bolt-up conversion. The driveshaft from the manual 240D would be my main question.

I think you on to something here. That car will be fun to drive if you build it with a turbo and manual four-speed.