1973 to 1976 A Body to Wilwood Caliper Adapter Kit

Congratulations, you have just found the way to remove 20 pounds of unsprung weight from the front end of your musclecar era Mopar. Using this kit in combination with the Wilwood Dynalite calipers will eliminate nearly 10 pounds of unsprung weight from each front brake assembly. All other parts will remain factory stock for easy service replacement.

SPINDLE - This kit provides the interface between the Wilwood Dynalite series of caliper, and the spindles that came stock on the 1973 to 1976 A body disc brake cars. Typical nameplates for A body cars would be Duster, Dart, or Valiant. These A body spindles are desirable since they bolt into any 1962 to 1972 B body car (RoadRunner, Charger, Coronet, GTX, etc) and allow the use of the late model, large bearing, uni-cast rotor. These spindles will also bolt into any E body car such as a Barracuda or Challenger, and of course, they work in the late model A body cars as well.

ROTOR - This kit works specifically with the 11.75 inch diameter rotor that came on the B and R body cars during the late 1970’s. These rotors are easy to come by at auto part stores and are relatively inexpensive. Ask for 1978 Cordoba rotors or Chrysler part number 4126545. The HD style has 10 ribs on the inside and is recommended.

CALIPER – This kit is designed to use calipers from the Wilwood Dynalite series. Wilwood part number 120-5094 is the correct part for an 11.75 x 1 rotor. These calipers have 4 individual 1.75 inch diameter pistons. This results in slightly less braking force than the stock sliding caliper. Therefore the front to rear brake balance will need to be adjusted in order to avoid rear wheel lockup. An adjustable proportioning valve, or the use of smaller rear wheel cylinders are two methods of making this adjustment. If you are unfamiliar with brake system modifications then you should consult professional resources for assistance. Wilwood only sells its calipers for racing purposes since they lack the weather seals necessary for street driven vehicles.

WHEELS – The use of the large 11.75 diameter rotors requires the use of 15 inch wheels. Stock Chrysler wheels should bolt on with no clearance issues, but since the factory produced these wheels in many different configurations, it is best to always check first for any interference issues. Aftermarket wheels need to be closely checked for proper offset and clearance. Many aftermarket wheels are rather poorly designed and manufactured. Often they do not have the proper indexing dimensions and therefore may cause interference issues. Check this area over carefully before driving the car.

INSTALLATION – Install the A body spindles per the service manual instructions. Note that the spindles are symmetrical and can therefore be installed on either side. The typical factory installation mounted the calipers to the front of the axle centerline. You can switch these spindles side to side in order to mount the calipers to the rear of the axle centerline, but beware of how that will affect the routing of the brake hoses.

Bolt the enclosed caliper adapters onto the spindle using either the stock ½ - 20 bolts, or the enclosed ARP bolts. Torque factory hardware to service manual specifications. The Wilwood calipers mount to the caliper adapters using the enclosed 3/8 –16 bolts. Torque these bolts to 35 ft-lb. Contact Wilwood for specific brake pad recommendations.

For an A , B or E body using the caliper mounted to the front of the spindle, the following brake hose recommendation should work. If you have a different setup, or mount the caliper to the rear of the spindle then you will need to work with your hose vendor for an adequate solution.

A 15 inch long #3 hose with one 90 degree end and one straight end seems to work the best. Goodridge makes an excellent hose assembly that is DOT rated and reasonably priced. Goodridge part number for this hose is D390315. You will need a 1/8 NPT to #3 JIC fitting at the caliper, and then a #3 Flare to #3JIC where the attachment to the existing hardline is. These are Aeroquip part numbers 2021-2-3S and FM10324-03P. All of these parts can be sourced from Oil Filter Service Co. in Portland Oregon if you cannot find a local source. Call OFSCO at 1-888-232-5126 or see them on the web at http://www.oilfilterserviceco.com