I bought front and rear drums "by application" to replace my 50 year old drums. My truck is a 1966 f-100 which came with a 352. It has a 9" rear end. The new front drums look like the old ones. No issue there.

In the rear the new ones look different. The old rear drums look like the fronts. The new rear drums have a lip which seems to be designed fit into the back plate. If I put the old rears next to the new rears the diameter and height are the same. This is what I bought (but I did not buy them from this store):

Front:
Centric Front Brake Drum 123.65005 | Car Part Kings

Rears:
Centric Rear Brake Drum 123.65000 | Car Part Kings

Is this just a different design that replaces the old?

 

Gets confusing sometimes for sure. I like to use RockAuto as well to determine application, does their site come up with the same centric part # drum? They usually have several different grades - cheap, standard service, and "pro" grades.

Cast drums make more sense to me. This is similar to OEM quality. ProTip: Have them given a "skim" cut or "light dress" by a machinist isn't a bad plan, just to make sure they aren't out of round, if they are stored improperly (on edge) or dropped, etc.

 

The only reason I did not use rockauto is because they were out of stock . . . I wound up using partsgeek. All sources list this as the correct drum, but the 'lip' on the rim is different. Instead of a channel it is a single lip. This is illustrated on the drawings of the products i linked to above. I am going to try to use them and see if they fit right. Probably just a different design, or someone put fronts on my rears before I bought them. The drums I removed were stamped fomoco so they were probably original.

 

The drums are different from 1968 on. A 1968 to early '70s rear is just about a bolt in in these trucks. Do you know if the rear is stock and unmodified?

 

My 1966 has a 9" rear which is stock according to the VIN plate. I do not know if there were any modifications prior to my buying the truck. The Drums look about 50 years old and say fomoco so those could be original. Other than that I do not now the history of the truck.

Thanks. I should start working on it next week so we'll see if it fits despite the different design. If you happen to know before though that would be great.

 

Well, every single rear drum for my truck I find on the internet matches the one I just got, so I am thinking that someone put front drums on the rear wheels by mistake, or they changed the design of the drum . . .

 

The rear drums are the same from 1948 to 1967 and the shoe is 1 3/4 inches. In 1968 they increased it to 2". Most 1968-up drums are available any any auto parts store but the earlier ones usually have to be ordered. I'm thinking they sold you the later drums.

 

I did some research based on what you said. Comparing the 66 drum to the 68-up drum I see the difference. Turns out I had a 68-up drum on my (supposed) 66 rear end, and I did order (and receive) the correct one for a 66. I ordered the correct shoes to match, so I assume everything I bought should go together well, and someone must have put an incorrect one on at some point. That or the rear end is not stock . . . ? But, like I said earlier the ford 9" rear on my truck does match the vin tags on the truck . . . so more likely the wrong one was on there?

 

I might be mistaken, but given the difference in depth, if the '68 on drum played friendly with the backing plate, then you have '68 on brakes.
That means the 1.75" shoes will be too narrow. You will be able to install them, but you will see that they do not rest squarely on the pads of the backing plate and your brakes will be terrible. Guess how I know.

The wide brakes can be swapped to earlier axle housings so either that upgrade has been performed or it is not the original axle.

Is the id tag still on the axle assembly? You can use the numbers on that tag to find out what it was originally for.

 

As long as what you have fits and works and you're good to go. Like Charlie I had under sized shoes on a truck once and it didn't brake good at all. In that case it was a '72 with the optional 3 inch front shoes but the last guy had put the smaller ones on.

 

Thanks everyone.

I just measured the old drums that I had, and the new ones I just received. They both have the same 2.11 inch friction surface. The 68-ups are wider (2.76 in.) so I do not have those after all. I thought I did because the "lip" is the same. However I can not see how the 'lip' would really make a functional difference once installed.

I'll see if I can check the axle tag for more information.

 

They fit just fine . . . thanks.