Originally Posted by eeghie
Mechanically yes, which means you'll be able to fit all the parts. The M3 front competition package dampers are in fact equal to the 1M dampers. However M engineers vary the spring rates with every 50 Kg of load. So depending on your cars (corner) weight, you will likely change the suspension behavior.
Assuming the weight of the M3 being higher than the 1M: when using M3 intended springs/coilovers, your 1M suspension will at least feel more firm that it would on the M3.
And have a relatively higher static ride height.