Front End Brake Upgrades
Coils for Classics
This article will be to inform the '78-'88 a & g-body owner of the 11"
& 12" front brake upgrades available, including parts needed, different
a-arms available, and a bushing discussion. Images will be added as
available.
The basic swap includes shorter aftermarket upper a-arms, and A, F, or B-body spindles,
which have 11" or 12" brakes. The gains of this swap are bigger brakes and a more aggressive
camber curve.
Parts of the front chassis:
On Mon, 31 Jul 2000 Carboy87SS@aol.com wrote:
> So Ive been doing some research on brake upgrades, and everything i see
> seems to center on 12" stuff... am I correct in assuming that the Monte
> SS brakes are 10.5 inch, or am I just making that up? Would using the
> 11" brakes off of a B-body car make that much difference? Would they
> bolt right on to the G-body spindle, or do 11" brakes necessitate the
> B-body spindles, making it obvious to go with the 12" setup anyway? Is
> there anyway to use 12" brakes without buying aftermarket a-arms? Any
> help is appreciated.
All 78-88 A/G body front brakes are 10.5" like you said.
All 70-81 F-body, and 77-96 B/D body spindles are the same height.
All 70-81 F-body, and 77-96 B/D body spindles are 1" taller than g-body
spindles.
All 70-81 F-body, and 77-96 B/D body spindles installed on a 78-88 A/G
body require the upper control arms replaced for proper ball joint angle.
All 70-81 F-body front brakes are 11" and have SAE studs.
77-96 B bodies had 11" brakes standard, but some(?) wagons, police sedans
and others(?) had 12" brakes. The 12" brakes require different spindles
but the calipers & pads are the same. The 11" brakes require a spindles
from an 11" brakes car, which are the same spindles on a B or an F body.
77-96 D bodies (Cadillac) always had 12" brakes AFAIK.
All 11" brakes we are discussing here are 4.75" bolt circle just like any
70-88 Monte Carlo.
All 12" brakes on the B/D bodies have a 5.00" bolt circle.
In order to use the 12" brakes with the right bolt circle, you should get
89-92 F-body 1LE option rotors. This is a way, although I hear rotors can
be drilled (but why?)
the upper a-arm and 12" or 11" brake swap complement each other
beautifully.
As far as parts, you need:
89-92 F-body 1LE rotors. These are just like the 78-96 B/D-body 12" rotors, but they
have the 4.75" bolt pattern instead of 5.00"
The following can be bought for a 78-96 B/D-body w/ H/D brakes.
- spindles, DS & PS
- inner & outer wheel bearings (2 each)
- inner wheel bearing seal (2)
- castle nut (2) (get this with used spindles if possible)
- cotter pin for castle nut (2)
- calipers, DS & PS (these should be the same as 77-90 11" brake calipers)
- stock 80's G-body brake hose (I believe this works w/ all 77-96 D52 calipers, it
- doesn't with 72 calipers and the 96 hoses don't work w/ g-body frame lines.)
- caliper pins (4)
- caliper pin sleeves & bushings & caliper hardware
All the spindles will work with the stock lower G balljoint except late '95 & '96 9C1 &
limo applications.
More to come later.