posi?

how do i tell if a rear end is posi or not?...i have the casting number is there a site i can look it up on

Do both wheels spin and leave marks when you light them up?

the rear end is out of the car...im buying a complete rear end from someone and i donno is it is posi or not...theyt "dont remember"

Well unless its a good freind i'm not sure if I would trust the "dont remember" part of it. if FormulaLT1 doesnt answer you soon you might pm him and ask him for sure on how to go about finding out for sure.

There should be a little metal tag on the diff. somewhere with an RPO code stamped on it...get the code and look it up on an RPO decoder

if i turn one axle what should the opposite do?

the same direction as the one you are spinning...

yeah the simplest failsafe way to tell is to turn one tire.. the other side should turn the same way.. This means its a limited slip (posi)

If it doesnt turn, or turns the opposite way, its an open rear

If you know the RPO codes thats the easiest way. If not then damone's way works too. Or the super fail safe way is to open it up and see. Good Luck.

John