diff oil? which weight??

[quincey]

Had my 2nd hand durango for just over a week now and after a quick tuesday night race at southend mcc-in which 1st time out and not even set up just put out as i got it,it won by a lap which i thought was really good seeing though i aint even ran there before..
any way when i got home i noticed that there was which looks like oil coming from the front diff,i looked in the manual and it doesnt state what oil is in it?... ive had a look on the durango set up sheets for southport and everyone is using 7000wt oil in the back diff but allsorts of weight in the front......any help to which would be a good starter weight for the front?
my driveing style is really flowy and i aint really agressive on the throttle i just keep it going and tend not to stop and start to much.
apart from that im really pleased with the car..