After a bit of advice please. I have got to do a engine swap in my 1998 's' reg 2.1 td 406. after my timing belt slipped and done some valves.

I have tracked down another engine,

but have been told by one person that i need to change the diesel pump over but on the other hand been told i dont need to by someone else
can anyone shed some light on this please, as i dont want to change the timing belt on this engine and pump to find out that i got to take it all apart again to put my old pump in again.
Also any one have any advice on the engine swap please. will be starting it xmas eve/boxing day
thank you in advance for any help