Sorry seabronc, you can't visually identify a 9" in quite the same way as an 8.8 or a Dana....
Flip the centre sections so you can look into the side gears for the left axle, the pinion yoke will be at the bottom of the centre touching your work bench.
Make sure you have enough light to see into the carrier through the adjuster.
An open carrier will have one side gear on the left side, a "posi" will have a two piece side gear that looks like there are two gears on the one side.
I hope that make sense, and that it helps....
Also, make sure that the side gears fit your axles (31 spline), kind of a bugger to find out you have the wrong side gears AFTER putting the centre in!!( older 9" diffs are 28 spline.)