changing the read end fluids
 

im just wondering what i need 2 change my rear end fluid....3 quarts of gear oil and some limited slip additive? its an 88 gt conv.
thnaks again

You'll also need a fluid hand pump as you have to pump the oil into the top of the diff.

Your local Ford dealer has some ncie synthetic fluid, but it goes for about $17/quart. I am running it now and would recommend either it or Royal Purple, which I am sure you can get for a better deal through Summit or another mail order house. Either mail order or the dealer can also set you up with the additive. Wear some old clothes, as changing it always seems to get a bit messy with the hand pump and all.

rearend oil change
 

Stay away from synthetic oil for the rearend...the friction modifier doew not mix well with the synthetic..also check on your clutch pac for your posi unit..if the clutch pac plates are metal you need two tubes of friction modifier instead of one for the fiber plates.