Info inside on stock rims & brake weight vs Centerline rims & Aerospace 12" brakes


Well-Known Member
Dec 15, 2002
Here is some weight info from my 87 GN and the Aerospace 12 inch billet brake kit and Centerline rim upgrade I have done. Drum info is also included for those who are looking to shed even more weight.

Stock rims (with cap): 29 lbs
Center line auto drags 15x10: 19 lbs
Center line auto drags 15x8: 17 lbs
Stock brake drum: 10 lbs
Aluminum brake drum: 5 lbs
Stock rotor: 17 1/2 lbs
Aerospace 12 inch billet rotor and hub: 9 1/2lbs
Stock caliper: 6 3/4 lbs
Aerospace 4 piston billet caliper: 3 1/4 lbs


Stock rims = 116 lbs
Centerline rims = 72 lbs (save 42lbs)

Stock drums = 20 lbs
Aluminum drums = 10 lbs (save 10lbs)

Stock rotors = 35 lbs
Aerospace rotors = 19 lbs (save 16lbs)

Stock calipers = 13 1/2 lbs
Aerospace calipers = 6 1/2 lbs (save 7lbs)

Total weight savings = 75lbs!!!!
68lbs of it is rotating mass!!!!
I have photos of the aerospace brake install process
email me at

Hope this helps
Now these can be used with stock upper and lower arms ? also ive got the stock vacume brake system from and 85 on my car , would the master cyl need to be changed . This may be my next upgrade.
Yep, I still have the stock control arms and spindle. The spindle needed to get the caliper ear sawsawed off, part of the spindle nearest the bumper sawsawed off, a 5 minute drumel to level off a spot for the caliper bracket, and 3 taps of the exsisting dust shield holes for the caliper bracket.

It might sound involved, but its really not. I am by no means a very skilled craftsman, but I sure do like the sawsaw now.:D
Sawsaw took about 5 minutes tops and the drumel the same. I was more afraid of screwing up the taps than anything else.

I am going to vacuum brakes on my 87 soon. The 1 1/8th master cylinder is plenty and has done just fine. No proportioning valve on this set up.

I have this same kit on my 69 GTO. That was even easier to install and man did that make a difference. I feel much safer in both cars now.

I have pics
I would like pics also.

I thought you were originally using the 10 3/4" rotor?

I thought you couldn't use 12" rotors with the stock a-arms?

I have four kids, and two are twins (9 mos), so I need something I can quickly and easily install myself. I don't want to mess with the 1LE or b-body a-arms and spindles if I don't have to.

I would appreciate some pictures as well. You bought the front or rears rotors? Cost??

Thanks alot

Shoot me an email guys and I will gladly send you the 6 or 7 pics I have of the set up.
I will probably do a page soon as I am getting my ride back next month.

I originally had 11 3/4 inch rotors but the kit uses a 1/2 spacer. So, my 265/50's were sticking out to much and I had to buy a new rim with a 5 inch backspacing. Then, the darn caliper barely hit the inside of the rim because of the larger backspacing so I had to send it back for the 10 3/4 rotors. The 11 3/4's looked great in there and would of helped on those frantic highway stops a few more feet.

The 11 3/4 kit did fit with the 15x8 (4" bs) and my photo shows it. But my greed for more traction and handling killed that kit from staying on my car.
OK, so,

The confusion lies within the title of the thread, "12" brakes".

You are now using 10 3/4" rotors, correct?

With the 10 3/4" rotors and four piston billet calipers from Aerospace, you just bolt them on and go, right?

No need for swapping out the a-arms and spindles?

Please advise-
Aerospace calls their kits 12" or 11", but really the rotors are 1/4 smaller than whatever size they are talking about.

My original kit (all the photos) are of the 12" (or really a 11 3/4) but I had to change to the 11" kit (or really the 10 3/4)kit. :confused: Ya I know, the numbers game.

They just bolt on with no new arms or spindles. They do use a spacer, and that might be a problem for someone with larger rim/tire combos or track guys. Some tracks might not like a spacer on the front tires.

I sent you an email for some pics.

I would like to see this "spacer". My wheels stick out a bit much already...