Arrrgghhh no...don't do that..
The whole point of these is the lighter weight of the four cylinder engine....nose is far more agile, far more responsive..
An E30 is so much more sublte and balanced than the later M3s which use brawn rather than balance...
Agreed they need to be looked after more.. but don't destory the balance by shoving a larger and lazier engine up front...
If you want the 6 go for a later m3