Why would you want to pull the heads?
If you are doing the timing chain guides, I'd replace the VANOS seals also.
Replace these:
Valley Pan Gasket
CCV hoses and oil separator, plus clean the drain tube
Rear coolant manifold gaskets (seen this often on E38 and E39, so should apply to X5 as well)
Lubricate your steering knuckle
Engine mounts?

__________________
*********************
Olympic Peninsula, WA, USA
-----------------------------------------
2005 Mini Cooper 100k, British Racing Green/Silver-Black
04/2002 4.6is 140k, Silver/Black-Alcantara *FOR SALE*
1989 325iX 270k, Diamond Black/Black
1984 318i 370k *SOLD* (First Bimmer)
Honorable Mentions: '71 2002, '87 325, '90 325ic, '92 525it, '93 325i, '94 530i