brake drum dilemma

[Dartman1967]

My 67 dart gt has rear drums that are 10 inch with the pad surface area 2-1/4 inches. I am told that the car should have 9 inch rear drums.....if the rear end was swapped out how do I find out what year it is?

Thanks

 

[mobileparts]

6 cylinders had 9" drums
8 cylinders had 10" x 1 3/4" -- that is what yours undoubtedly is --
the drum width is actually calculated by the width of the shoe....
the actual drum depth is greater since the shoe does not go from
bottom lip to upper lip....
A "Dart GT" is 90 + % 8 cylinder -- so should be 10" x 1 3/4"

(Canadians may have a different answer -- since some cars that went
north of the border, eh?, were equipped with lighter duty than here in the USA)....

 

[Dartman1967]

6 cylinders had 9" drums
8 cylinders had 10" x 1 3/4" -- that is what yours undoubtedly is --
the drum width is actually calculated by the width of the shoe....
the actual drum depth is greater since the shoe does not go from
bottom lip to upper lip....
A "Dart GT" is 90 + % 8 cylinder -- so should be 10" x 1 3/4"

(Canadians may have a different answer -- since some cars that went
north of the border, eh?, were equipped with lighter duty than here in the USA)....

Thanks for the response. The guys that are doing the work for me have said that the front drums are 10 in with "friction pad" of 37/8 inches while the rear is 10 in. with the "friction pad of 21/4 inches. the rear studs measure 5x 41/4.

Does this make sense to you? is the 5x41/4 stud measurement the same as 5x4?

 

[furyus2]

When measuring bolt pattern, you put the tape measure on the outside of one stud. Then measure to the center of a stud across from the first stud.

 

[RedFish]

We know it's supposed to be a 5 on 4" bolt circle but... at 50 years old and unknown history, It my have a later model rear with 5 on 4.5" circle and wider linings.