[wmurrell]

Was it possible to order aluminum drums with the metallic brake option in 1965? I would have thought that the metallic brakes would be too aggressive for the aluminum. Thanks!
Bill

[Ken K]

Only the outside is aluminum, they are steel lined. You can have them resurfaced just like a normal brake drum.

[60sstuff]

You could order one "or" the other (metallic linings or aluminum drums) but not together.
The metallic brakes were designed to work better with high heat.
The aluminum drums were designed to do the opposite.

[wmurrell]

Thanks for the info & photos 60sstuff!

If you ordered a 3.90 rear, it forced the metallic brake option. Since the metallic brake option cannot be combined with the aluminum drums, it would dictate that all the cars with aluminum drums would have to be non-3.90 rear cars.
I have copies of the billing history cards for ~70 ’65 GTO convertibles and checked to see if this held true. I found 7 cars with factory aluminum drums. Six had a 3.55 rear and the seventh had a 3.23. Learn something everyday!

[Ken K]

The big difference is you can sell the aluminum front brake drums for big bucks. They were selling for crazy money on ebay. Metallic pads or aluminum drums are not in the same league as disc brakes. It's the haves and have nots.

[John V.]

The metallic brake option also came with specific brake drums.

I do not know how they differed from the drums used with the standard brakes, but specific drum p/ns were specified with the metallic brake option.

So it wasn't just the shoes that changed.

IIRC, you could order the metallic brake drum option with any ratio from 3.08 and up '65, 3.23 and up in '64. And as Bill points out, if you specified the 3.90 ratio, you were required to order the metallic brake option. There was a factory 3.90 axle with standard brakes but it was not used for the GTO (I think it was only used for a 6 cyl application).