Hi all, I would like your thoughts please. I have a mk3 spitfire with a noisy dif. When the car was serviced recently it was suggested that if I decide to replace the dif with a rebuilt one then it would be a good upgrade to change it for a later set up, ie mk4. It was said that with the dif and rear axle upgrade this would improve handling. I am also considering exchanging the gearbox for a full syncro'd one at some stage when funds allow and adding overdrive which I don't have at the moment. However I think my decision what to do regarding the dif will need to be brought forward because it has started to leak more and its time to replace the seals. My options are to get the seals replaced on my existing dif and carry on with a fairly noisy dif or go for a replacement. If I go for a replacement ive got to decide if I stick with the original Mk3 set up or upgrade to later set up. If I stick to the existing set up and replace the dif then Ive got an identical exchange unit. If I go with the upgrade then I will have to pay the non exchange supplement. The question is what to do??