I HAVE A QUICK QUESTIONS ABOUT A REAR DRUM TO REAR DISK CONVERSION. I HAVE A REAR AXLE IN MY CAR OUT OF AN 88 FORMULA. IT IS A B/W 9 BOLT 3:27 POSI DISK. I HAVE AN 82 FIREBIRD THAT I AM STRIPPING AND PARTING OUT. I WANT TO KEEP THE REAR AXLE AS A SPARE IN CASE I BREAK MY AXLE I HAVE IN MY CAR NOW. I AM NOT SURE HOW MUCH TORQ A STOCK AXLE CAN TAKE(I AM PUTTING OUT 433 FT LBS RIGHT NOW) SO I WOULD LIKE TO BE A BOY SCOUT AND BE PREPARED IN CASE SHE BLOWS UP. THE AXLE ON THE 82 HAS A REAR DRUM SETUP. I AM NOT SURE IF IT IS A B/W. MY QUESTION IS CAN I SIMPLY SWAP MY DISK BREAK PARTS TO THE REAR DRUM AXLE IF I NEED TO??? IF I HAD TO PUT IN THE 82 FIREBIRD AXLE IT WOULD ONLY BE TEMP UNTIL I WOULD JUST BUY A FORD 9 INCH.I JUST DON'T WANT TO GO AND BUY ONE RIGHT NOW IF I DON'T HAVE TO JUST YET. http://members.ebay.com/aboutme/84transam/

 

(Wow, man, turn off the caps lock key! This ain't the early 80's anymore! ) The mounting flanges on the ends of the axle tubes are different for drum rears than disc rears.

It's been theorized that if the flange of the drum rear was cut down, it would accept the mounting plate for the rear disc. But, the hub of the axleshaft on a drum rear is too wide to fit inside a rotor! So the hub would need to be turned down until the rotor can slide over it.

So; it won't bolt in, but it might work. But as you know, the '82 axle will bolt onto the '88 with no problems.

Now don't forget- in 82 & 83, GM was using SAE (standard) threaded fittings for the brake lines. They moved to metric in '84. What's this mean? You couldn't connect the '82 brakes up to the '88 without modification. The modification requires either:

1. You'd need to either find adapters for the brake hose

2. You'd replace the '82 (SAE thread) wheel cylinders with '84-up (metric thread) wheel cylinders, and buy/make new lines for the rear axle that use the metric ISO bubble flare fittings.

3. Make custom brake lines that have SAE fittings on the wheel cylinder end, and metric on the end for the brake hose.