The engines are not entirely the same. The X5's engine is an updated N52. It's pretty much a hopped up 328. It has the newer DME and plastic valve cover. The '06 330 has a magnesium valve cover and older DME.
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here!
| Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors