You will have to swap complete intake, maybe the throttle body (different position of the sensor, and different angle of vacuum feed line. There is a thread about this) oil pan, pick up, complete wiring harness.
About the serpentine belt, if you want to use it (assuming the E36 engine comes with it...b/c not all E36 had serpentine belt), you will have to bend the dipstick, as it will be in the way of the belt.
The valve cover is the same, it is different in the M44, but not on the early M42 E36.
I hope this helps!!