Does anybody know if the xc90 struts would drop into a 2003 s40 looking to lift it but this is the first volvo I’ve ever really messed around with

 

you'd have to side by side the struts but its not very likely to be the same. The gen1 S40s are a different platform from the bigger Volvos and had more components in common with a Mitsubishi than other Volvos :-) The S40 struts use a different style strut mount, and a very long coil spring compared to the V70s etc.