CPU upgrade E8200 -> Q9400

Hi all,
I'm planning to upgrade my Hackintosh.
That's my actual setup:
MB: ASUS P5KC RAM: 4 GB DDR2 800 Mhz CPU: INTEL E8200
SYS HD: 320GB MAXTOR SATA RAID: 2x500GB MAXTOR SATA's
GPU: NVIDIA 9600GT OSX: 10.5.7 Retail
I've a question for you.
I want to upgrade to 8GB DDR2 and change the dual core E8200 with a Quad Q9400.
Do you think it will be safe? I have to expect problems at booting? I've update the BIOS to the latest version to be sure the new CPU is recognized.
Do you think that the OSX installation I did it with the E8200 will screw up after change? Must do anything before upgrade?
Thank you for all your answers.
Ciao