Identifying drums

[coffeedart67]

I am getting ready to order new brake lines and I want to replace the lines that run between the wheel cylinders. How do I determine what size brakes I have. I have the front suspension with brakes at home but the car(with fender tag is about 30 miles away). It is a 67 Dart GT Convertible, 273 (2 barrel) automatic, and has drums all the way around. Also what wheelbase is my car so I am sure to get the right line from front to back?
Some more brake quesions. I took the fronts off and measured and they measure 10" across the inside, so 10" right? Are the hubs available anyplace as 2 studs on one hub and one on the other are welded to the hub. Did some checking and my car is 111" wheelbase, correct? On one drum there is a hole in the side, and the other there is a spot with wled on it in about the same location, what is this? My proportionaing valve has been off and open for about 2 years, should this be okay to use or should I replace it?
Thanks

 

[coffeedart67]

Heres pics of the hole

 

[wjajr]

You have 10” drums, measure width of brake shoe as some later cars had wider shoes to get correct part.
Grind off the weld bead holding stud, press out old studs, and replace old studs as needed when installing new drums.

That hole is an imperfection, or someone punched it out beating on the drum trying to free it up at some point in time… Who knows for sure.

 

[BillGrissom]

I also have 10" drum brakes on my 65 Dart. wjajr is correct, 10" means the ID. You should also find a max dimension for machining on the drum, to ease your concerns.

The studs are not welded, but "swedged" to hold the drum on (swedge is a pinch of the stud surface). I assume that was for manufacturing ease. You don't need the swedge since the wheel holds the drum tight. Old brake guys had a "swedge cutter", kind of like a hole saw I expect. Today, you need to improvise (Dremel tool w cut-off wheel, grinder, ...). Worst case you can cut off and drill out the studs and replace. Save the hub, since not a wear part and hard to find. The good part is that it sounds like your drums might be original (low mileage car) since only the factory would swage the studs.

Treat your rear drums nice. You can't buy new and used ones are ~$80 each. People are pondering solutions (drill stud holes in a BBP drum, ...).