For technical reasons, this is not necessary as long as the spring is preloaded. If no preload is achieved, shortened sports
shock absorbers are required. BILSTEIN produces these sports dampers under the product name
Bilstein B8.
For example, the EIBACH Pro-Kit spring sets are usually suitable for the
standard shock absorbers and
BILSTEIN B6. Of course you should check whether the struts are still ok. Wear due to mileage, driving behavior or the age of the vehicle are good reasons to replace the dampers with just one conversion.
Because the same applies here:
When replacing springs or shock absorbers, always have the
track readjusted.