Okay, I have been reading on this site for a while and I am totally screwed up as to what is a posi rearend and what is not. I was always told that a posi rearend was the one you wanted. If you do a burnout with posi both wheels will spin at the same time. From what I have been reading I get the picture that Posi is the one that will only let one wheel spin and give you "positive traction". so what is Posi? Both wheels spinning on a burnout or just one? Which is better if you want the best launch ? I have the limited slip and I can't do a decent burnout to save my life.

a posi will burn both wheels you want this for traction..it will act as a locker until a certain amount of force is applied to one side, then it will open. ei, while turning. A limited slip and posi are the same thing. Posi is gm's nick name for limited slip, sure-track was used by ford or mopar, i cant remember, but there all limited slip. If your only burning 1 tire, your posi is busted or you have an open diff.

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1984 Z51 Auto, Ported and polished intake, K&N, MSD, Ram air/Cold air intake, no cat, no AIR, no egr, no swirls plates