1966 dart front brakes?

Bennd52 said
Ok, so! i have a stock 66 2 door dart. It has a 225 slant six, all original accept the hood and right front fender. I ordered front brake drums, and shoes. Turns out the drums are 3 1/2" wide. My factory are smaller, and the question is; what has this size of drum and is it an easy swap? Do I just need the backing plate? It is only about a half inch wider which would be an improvement in my book!! Any feedback on this would be appreciated!

The nominal brake size is the inside diameter by the lining width (not drum width).
These are in the back of the Service Brake Chapter of the Dodge Service manual. Download a copy and/or buy a copy.

Shoes are stamped with a Friction manufacturer's frame number.
It will look like this. This number is not what you'll find on your car, just an example.

Some replacement part manufacturers use the FMS in their part number. Some do not. But its a way to check that you have the right one, and also a way to ask for the correct ones at a real parts store or brake reliner.

You can pick up some additional info and tips in Master Technician Service Conference - Chrysler's Training for Mechanics
Relevant info for your brakes are in 1963, 64
Before that is different type of system.
1967 The master cylinder changed. 1969 the drum adjusters changed and so did the shoes.