Q8400 to QX9650 or Xeon X3380

So I have Asus P5QL-Vm EPU motherboard and it can support Duo Core 2 Quad and extreme
using a Q8400 CPU on it. I am wanting to upgrade the CPU, funds are tight but..

Would this mean, I believe that the best I could get would be the QX9650 or a QX9550 on this older system board?

How about the Xeon Series CPU and wondered if a X3380 ( that side by side comparison at Intel page looks like there would be no reason for it to not work, except its not mentioned on the manual.
has anyone done a Xeon transplant on a Duo Core 2 Extreme/Quad capable board?

To spare some headaches of searching,
The board support LGA775, 45nm technology and FBS runs at 1333/1066/800mhz I would like to get 1333 if possible, also supports Hyper-threading and EIST
I did a cpu compare http://ark.intel.com/compare/41094,33924,38512,33921

thank you for your input,
Note: The cpu is only what I want to upgrade, nothing else. PSU is 650w corsair and I got 8G of Ram on it. thanks for the thoughts ...
 
you should check the specs on that board on the Asus website. they may have added additional supported CPU's with some BIOS updates
Yeah been there done that, no mention of Xeon. but to my surprise mentions 65nm technology chips though the board indicates 45nm tech only. Core 2 Duo E6540 CPU for example.
which led me to my extrapolation to Xeon, but seems that is a different beast compared to 65nm and 54nm difference between CPUs

thank