correct diff

hi, got my eye on an '04' td5 110 csw and was wondering if anyone can tell me what rear diff it should have. my 110 300tdi csw (98) has a salisbury diff and i was expecting to see the same on the td5 but it looks just like the one i had on my 300tdi 90. would appreciate any information. would also like any tips on what to look for before i waste my hard earned cash!!.

they did go away from salisbury diff on later motors cant remeber exact date

thanks for that. any views on which is the better diff??

salisbury is better its very big ,so is more expensive and will use more energy to drive it presumably why they moved away