Which propshaft do i need?

Hi all,
I need a new propshaft for my landrover, the problem i have is i do not know what the original is from. Its just used for off roading and nearly everything has been modifyed by the previous owner and has a range rover chassis + axles with a series cab with an isuzu engine.The length of the propshaft is 500mm. I have compared it to a friends defender and his is longer, also a range rover which is also longer, the only option i havnt tryed is a series prop.
There is a number stamped on it which is 556449, i have typed this into google and it comes up on a couple of sites but there are no pictures so am abit wary of purchasing.
Any help would be greatly appreciated.
Thanks,
matt

Well..thats a front prop for a 109 series....frankenstein lives.

If thats whats on it..and its worked..fit another, but try STC574 as part number.

Thanks, il have a search for one now

Hi
I ordered an stc574 which arrived today, however it is too long, its around 20cm longer than the original that was fitted. Any idea's?
Thanks