I have a 84 Z28 5speed that I want to do some autocross and time trials racing with. I also have a 83z with a posi 370 rear disc brakes car for parts. Would it be beneficial to swap rearend and use the posi unit for the 84 ca?
The 84 car now has a open axle drum brake set-up.
thanks Lee

 

Yes, it would be a good swap. The standard differential is going to allow the rear tire on the inside of the turn to spin when weight is shifted to the other side in a hard turn. The posi rear end will keep power going to the tire with the most load on it so you will be able to power through the turn better.

Now if this is a Governor Lock differential then it might not lock up in a turn. The Governor Lock works like a standard differential during normal driving, but locks up when one tire begins to spin faster than the other. The only problem is that the governor only works at very slow speeds, and once you get up to around 20 MPH or less the governor no longer works. If you are going through a turn at a speed higher than the governor will work, then the differential will not lock up.

If this rear end has an Auburn differential in it then it will work better, as long as it is not worn out. The Auburn wears out pretty quickly as compared to other differentials, and they are not rebuildable. If you have an Auburn then you should inspect it before you go to the trouble of swapping it.

 

how do I tell if its an auburn?

 

Take a look at these. The one on top is a Governor Lock and the one on bottom is an Auburn.