1966 Coronet, 73-76 A-Body Steering Knuckle & Disc Brakes

[LSS&B]

Suspension Height Question:
If a 66 Coronet is converted to front disc brakes using 1973-1976 A-Body knuckles and calipers, does that change the suspension height? If so, how much in inches lower or higher?
Would A-body alignment specs be required to align the car?
Thanks, Ben

 

[Kern Dog]

No, the spindle on the knuckle is in the same relative position.
The alignment can be where you want, I suggest to avoid the factory specifications since the tires sold today are capable of handling SO much better than the tires our cars originally came with.
Even if you aren't interested in turning corners fast, a few changes in the alignment settings will allow the car to react better in an emergency situation.
I suggest 1/2 degree of NEGative camber, 1/8" toe IN and as much caster as they can get, hopefully at least 2 degrees POSitive.

 

[gkent]

OP ... are you planning to use "Mopar" parts for this swap - calipers, brackets, rotos, etc.? If so, which size rotors?

 

[YY1]

A body calipers and spindles would suggest 10" brakes.

11 inch would be possible if rotors and caliper brackets from another car were used.

 

[gkent]

Was hoping the OP would answer himself !!!

 

[autoxcuda]

A body calipers and spindles would suggest 10" brakes.

11 inch would be possible if rotors and caliper brackets from another car were used.

73-76 A-body disk are 10.75" diameter. Same basic diameter as they used on 66-74 B/E/A body disk brake cars. 14" rims will fit over them.

You can install 11.75" diameter rotors from certain mid 70's B-body cars on 73-76 A-body spindles by using a different caliper adapters sold here: Mopar 11.75" Disc Brake Slider Caliper Brackets Those require 15" rims. All wear parts available at parts stores.

 

[LSS&B]

OP ... are you planning to use "Mopar" parts for this swap - calipers, brackets, rotos, etc.? If so, which size rotors?

Yes. 1973 A-body 4.5 inch lug, 10.75 inch rotors. A-Body OEM knuckle/spindle, calipers, caliper brackets. Nothing aftermarket.

 

[Kern Dog]

A body calipers and spindles would suggest 10" brakes.

11 inch would be possible if rotors and caliper brackets from another car were used.

Actually, the 1973-76 A body disc knuckles were fitted with a rotor that measured 10 3/4”, a number most often rounded UP to 11”. Nobody I know of ever called them 10 inch discs. These were excellent brakes for the A body and were used in most of the rear wheel drive Mopars all the way to 1989. Some heavier models used a 11 7/8” rotor that was commonly called the 12” disc. I had them on my red car until I changed to even bigger 13” discs that originally were used on specific 1994-2001 Mustang models.
Obviously, the 11” setup worked well enough for Chrysler to use them even on the heavy Fifth Avenue cars that pushed up close to 3800+ lbs. They are a great option as an upgrade from front drums.

 

[MWbirdLOVER70]

73-76 A-body disk are 10.75" diameter. Same basic diameter as they used on 66-74 B/E/A body disk brake cars. 14" rims will fit over them.

You can install 11.75" diameter rotors from certain mid 70's B-body cars on 73-76 A-body spindles by using a different caliper adapters sold here: Mopar 11.75" Disc Brake Slider Caliper Brackets Those require 15" rims. All wear parts available at parts stores.

@charlescook

 

[LSS&B]

Actually, the 1973-76 A body disc knuckles were fitted with a rotor that measured 10 3/4”, a number most often rounded UP to 11”. Nobody I know of ever called them 10 inch discs. These were excellent brakes for the A body and were used in most of the rear wheel drive Mopars all the way to 1989. Some heavier models used a 11 7/8” rotor that was commonly called the 12” disc. I had them on my red car until I changed to even bigger 13” discs that originally were used on specific 1994-2001 Mustang models.
Obviously, the 11” setup worked well enough for Chrysler to use them even on the heavy Fifth Avenue cars that pushed up close to 3800+ lbs. They are a great option as an upgrade from front drums.

I thought I was using @YY1 terminology (like at 10" torque converter is really 10.75")
My mistake. So is the 1973 A-Body Steering Knuckle same height as stock 1966 B-body steering knuckle?

 

[LSS&B]

Thanks for all the advice, but my question remains about front end height.
Is the 73 A-body knuckle shorter than 66 b-body knuckle?

 

[RemCharger]

No, the spindle on the knuckle is in the same relative position.
The alignment can be where you want, I suggest to avoid the factory specifications since the tires sold today are capable of handling SO much better than the tires our cars originally came with.
Even if you aren't interested in turning corners fast, a few changes in the alignment settings will allow the car to react better in an emergency situation.
I suggest 1/2 degree of NEGative camber, 1/8" toe IN and as much caster as they can get, hopefully at least 2 degrees POSitive.

My mistake. So is the 1973 A-Body Steering Knuckle same height as stock 1966 B-body steering knuckle?

Thanks for all the advice, but my question remains about front end height.
Is the 73 A-body knuckle shorter than 66 b-body knuckle?

Kern Dog gave the perfect answer in post #2.
The knuckles are the same.

 

[autoxcuda]

Thanks for all the advice, but my question remains about front end height.
Is the 73 A-body knuckle shorter than 66 b-body knuckle?

Both knuckles are the same height. But you should align the car again.

 

[LSS&B]

Kern Dog gave the perfect answer in post #2.
The knuckles are the same.

Thanks for stating the knuckles are the same.
Kern Dog said "Same relative spindle position." As to height, this sounds like a ratio for distance between spindle center and top of knuckle vs. bottom of knuckle
Example
Regardless of unit of measurement of height.
Say the OEM distance from top of knuckle to spindle center is 6 and distance from bottom of knuckle to spindle center is 3
A replacement knuckle would have same relative spindle position IF:
*distance from top of knuckle to spindle center is 4 and distance from bottom of knuckle to spindle center is 2
*distance from top of knuckle to spindle center is 12 and distance from bottom of knuckle to spindle center is 6
However the heights of knuckles would not be the same.
Relative spindle position is important, but my original question was about knuckles being the same height. I thought no one answered it, so I repeated it.

You say the 1966 b-body and 1973-1976 a-body knuckle/spindle are the same (except that one has caliper mounts and one does not), great! That answers my original question.

 

[gkent]

Relative spindle position is important,

The knuckle height is important because different heights will change the suspension geometry. But spindle height just changes ride height - this is a very popular way to do it and there are a number of companies offering these in the aftermarket. Very few , if any, for Mopars though but what else in new !!