I think i know what you mean,
most of these cars are lowered with lowering springs to the front and lowering blocks to the back! The cost is about 60£ for the springs (might be cheaper) and an other 25£ or so for the blocks, that should result in a lowering! So your wheels will be closer to the arch!

Classicwede (member) has a topic about these things, he sells them, so check that one out!http://www.volvo300mania.com/forum-uk/v ... php?t=1804

This is how the rear is done!http://www.volvo300mania.com/forum-uk/v ... =13&t=8890