Chiptuning 250 D

Hi guys, I have to buy a 250D year of construction 91. However, the car has a little bit of performance. That’s why I was thinking about chip tuning. I’m not sure if you can do that with such an older engine. I actually wanted to drive it for about 4- 5 years. If someone has had experience with it before, I would be happy if I could get an answer.