My '88 IROC was originally built with a 2.77 posi rear, and 4-wheel disc brakes.

At some point, someone swapped the rear with a 2.77 open rear, and drum brakes.

I've just purchased from another member a 2.77 posi rear with discs, including the parking brake cable.

I have a suspicion the previous owner didn't bother changing the proportioning valve when they swapped the differential, and went to drums, which could mean the proper proportioning valve is already on the car, once I put the original style brakes back on the car.

How do I determine which valve is currently installed on the car?

 

A buddy found the information for me..

Disc/Drum: 14089495 sticker NC

Disc/Disc: 14089497 sticker NB

As I suspected, the previous owner didn't bother changing the valve.

 

Hello, How has the braking been this summer?

 

Sorry I've been so slow to reply, I've been travelling on company business.

The brakes have been surprisingly good, considering the incorrect proportioning valve is installed. I've not yet had the time to replace the rear axle, which will get the proper rear disc brakes on the car.