Simple?are all disk break rear ends posi units

 

No. Just cause you have one does not mean it has the other.
In some of the ones I'm parting out, I had a '84 TA with disk brakes, 3.73 gear, open (non posi)
I have a '92 z28 with drum brakes, 3.08 gear, posi.

 

Like Night rider327 said they are a mixed sort. My rear came out an 84 Z28 drum brake posi. Every Z28, Formula, or Trans Am I ever had was equipped with a posi even though I know they weren't all equipped with it.

 

OK,let's fill u in on what I've learn about this disk brake unit. Its a 9 bolt Borg warner with a tag placed under one bolt head. Tag says gear ratio 3.27 and Vin decodes 5.7tpi. Its an 88 formula with no console seats or rug. There are raised numbers and letters on the bottom look like g11f7 . hard to tell. I couldn't see anything on front face passenger side axal.this Haynes manual shows all Borg are posi. Anything?

 

You answered your own question.

9 bolt Borg warner
3.27
posi

 

9-bolts are almost all posi and disc.

I'd say "all", but somebody posted a photo of one a few years back that had no posi and drum brakes. Creepy looking.

 

I have a 9 bolt open and drums.

 

Posi are usually shot though.

 

Wonder if them drum non posi Borg's are stock? What gears they come with?

 

I would recommend going with a 10 bolt from a 98 and up ls1 car, they will bolt in and have a Torsen LSD. Or go aftermarket. The posi in the BW 9 bolt is usually shot and they aren't much stronger anyway.

 

That would take a few dollars to do. I will keep that in mind when I get that far,if this one has any issues. I'm not planning on running anything hard anyway. I just want thing to work right and not brake down every other day.