I picked up an 89 formula from a friend after his spoiled daughter didn't want it , the first thing I noticed when I drove the car is the rear brakes don't work worth a crap , well upon further investigation it's a drum brake 10 bolt with yellow marker numbers on the cover (salvage) . Oh and the obviously stock 16 inch wheels have ws6 center caps . I've looked in all the locations for a build sheet for the car but nothing .
I want disk brakes back , how can I tell if the proportioning valve is for the disk or drum rear ?
I can get a 94 rear but I thought I read the width is different ?
Are the brake lines exactly the same ?
The e-brake works now (on sand anyway) isn't it a straight swap to ?
Any and all help will be greatly appreciated

 

A full rear swap would be the easiest but a 4th gen rear will be 2" wider per side, your wheels will stick out a bit. There's no way to tell the prop by just looking at it, the differences are internal. What's the gear ratio in the rear you have? If it's a good one (3.23 and higher or a posi), just swap the rear drums over to discs and go on. Brake lines are slightly different between disc and drum but nothing to fret over, it's an easy swap.

Ed

 

Hey Ed , I considered swaping the brakes but the drum brake axel has a growl , when the car was purchased by my friend the diff cover was leaking and very low on 90 wt , so I have a feeling the rear end thats in there now has had better days . I don't know the gear ratio but the speedo is off considerably , I would guess a high 2 series gear . I guess the spline counts are the same on the two carriers but to do it right with pinion bearings , carrier bearings and seals ( crush sleeve ?) not to mention the set-up time plus a disk brake swap - I think I'll find a new axel . Thanks Ed

 

Here is a pic of a 3rd gen Camaro with a 4th gen rear, and the stock rear 16" wheels. To me, think they are a perfect fit.