X4440 mezzanine board installation help.

Hi,
I plan to install an additional Mezzanine CPU/Memory board. The X-option is X5391A. I checked FEH for information:

X5391A [S]

16 DIMM Slot, 0MB, 2 x 2.8GHz AMD Opteron 6-Core 8439 SE CPU/Memory Mezzanine Card

310-0128

Opteron Heatsink

n/a

330-4622

Air Duct

n/a

371-4686 [F]

2.8GHz CPU, Opteron 8439 SE, 6-Core, D0 Stepping, 105W

n/a

540-7953 [C]

CPU/Memory Mezzanine Assembly

540-7597 [C]

• 330-4622

• Air Duct

n/a

• 541-2769

• Tray

n/a

541-2906 [C]

HyperTransport Riser

n/a

From the CPU/Memory Mezzanine Assembly installation notes I found :
"Replace Air Duct 330-4433 with Air Duct 330-4644