i am going to look at an 84 H/O. it will likely be a parts car. i looked at it almost 2 years ago and kept it on the back burner because the guy was not in a hurry to get rid of it. i am wondering where on the rear end to look for the code to know that it is the 8.5 posi? the price is high enough that if it don't have the posi it will not be worth buying. i hope it is good enough to keep as a driver because i want to drive it back and forth to work if i can.

 

Here's what you're looking for:

The 7.5 has pointy fangs like a vampire on the bottom.

The 8.5 has more of a square housing bottom.

 

Here is what the rear end under my 84 HO looks like it is the posi rear. The tag attached to the top cover bolt is the tag that specifies limited slip additive in the oil. HTH

 

J Chicago does that 7.5 have the new style self clearancing pinion gear in it.

 

There are plenty of 80's 442's & H/O's that did not have a posi,but the housing itself is the valuable piece.