Brake shoe size

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I was looking and there is lots of listings for 10 x 2.5” fronts for like 74, and 76 darts etc....

Be worth a try to go to a shop, have them get a set in and compare them. Maybe you’d get lucky and they’d be the same....
 
There were front brake backing plate changes from 72 to 73.
Do not know if it changed the shoes tho.

edit...
might have both back on the shelf to compare...way back on the shelf...
 
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73 up left, 72 back right
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shoes look very similar except 73 up shown is 10x2-1/2 and 72 back is 10x 2-1/4.
Not sure what all has to change for a wider shoe, other than the obvious, drum, shoes...
Wouldnt the plate have to change as well to keep the geometry of the cyl. correct?
Or is there a different wheel cyl....hmmm...
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100_4891.jpeg
 
That’s a good post. Man, we’re only talking 1/4” here (1/8” more each side from centreline of the show) I wonder if it really matters?
 
I'd think it could make a difference.
The actuator rod will be at a slight angle coming off the hyd. cyl. piston.
Changes the force angles a bit, might make the piston try to **** in the bore.
Then again there may be enough "play" in the system to take up the 1/8"...
 
Jimacuda said:
73 up left, 72 back rightView attachment 1715451159

shoes look very similar except 73 up shown is 10x2-1/2 and 72 back is 10x 2-1/4.
Not sure what all has to change for a wider shoe, other than the obvious, drum, shoes...
Wouldnt the plate have to change as well to keep the geometry of the cyl. correct?
Or is there a different wheel cyl....hmmm...
View attachment 1715451160View attachment 1715451161
Click to expand...

If you measure the offset on the backing plate you'd know for sure. Just lay a straight edge across the back of the plate and measure down to the center hole.

Clearly the bolt pattern on the spindle is different, but the pressed indent for the spindle actually looks the same between those two backing plates. At least in the picture anyway.

I did a little looking, the wheel cylinder part number changed going from the '71 parts catalog for the 10x2.25" front drum set up to the '73 parts catalog for the 10x2.5" front drum set up. The part number for the 10" rear drums stayed the same between those years.
 
72bluNblu said:
If you measure the offset on the backing plate you'd know for sure. Just lay a straight edge across the back of the plate and measure down to the center hole.
Click to expand...


Sure, make me go measure them...sheesh...:lol:
 
2-1/4" is approx. 1.45"
2-1/2" is approx. 1.57"

So it looks like backing plate offset dictates shoe width.
I suppose you cant really go outboard much with the increase in shoe width without effectively hitting the back side of the wheel...DOH! :lol:

A few other differences as well...


100_4899.jpeg
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100_4901.jpeg
 
Jimacuda said:
2-1/4" is approx. 1.45"
2-1/2" is approx. 1.57"

So it looks like backing plate offset dictates shoe width.
I suppose you cant really go outboard much with the increase in shoe width without effectively hitting the back side of the wheel...DOH! :lol:

A few other differences as well...


View attachment 1715451317 View attachment 1715451319 View attachment 1715451320
Click to expand...

Great info! Thanks for doing that, should clear a few things up for folks with the 10” drums up front.
 
72bluNblu said:
Great info! Thanks for doing that, should clear a few things up for folks with the 10” drums up front.
Click to expand...

an 1/8” difference in offset, but now it would be good to compare the two listings of wheel cylinders against each other. Maybe they accommodate the different offset’s so if you changed everything in pairs you’d be okay?.....
 
glad I didnt save it all for no reason:rofl:

well, I did stack them neatly on a shelf out back a couple decades ago as they were stripped...
then promptly lost them as things collected in front of them...:D



100_4136.jpeg
 
4mulas said:
an 1/8” difference in offset, but now it would be good to compare the two listings of wheel cylinders against each other. Maybe they accommodate the different offset’s so if you changed everything in pairs you’d be okay?.....
Click to expand...

look at the backside pics...the wheel cyls. physically wont interchange.

As I see it you have to match the drum to the shoe width to the backing plate offset.
 
Totally. Didn’t look but that’s 1 year old peg board 101 stuff. Square don’t fit in round and vice versa. Lol
 
4mulas said:
I see listing for 10 x 2 1/4” shoes which are probably it
Raybestos 332pg
Wagner PAB332
And in a lesser grade:
Bosch BS332
Wagner Z332

Don’t know if that will help but I think these are probably the ones?
Click to expand...


I hope I am not high-jacking this thread, but I pulled a drum off of the back of my 64 dart, 8 3/4 10" x ?, because it locks up when I step on the brakes, and noticed that there is a good 1/4 inch of more of unused drum on one side of the shoe. The shoe measures less than 2", so I am assuming someone, not me, put the wrong shoes on it. The question is do I need 2 1/4 or 2 1/2 shoes ? or do I need to measure the drum better? I know I need a different proportioning valve, that is a different subject.


Thanks


PS. dual master, front disks from a 69 and all small pattern.
 
trapster said:
I hope I am not high-jacking this thread, but I pulled a drum off of the back of my 64 dart, 8 3/4 10" x ?, because it locks up when I step on the brakes, and noticed that there is a good 1/4 inch of more of unused drum on one side of the shoe. The shoe measures less than 2", so I am assuming someone, not me, put the wrong shoes on it. The question is do I need 2 1/4 or 2 1/2 shoes ? or do I need to measure the drum better? I know I need a different proportioning valve, that is a different subject.


Thanks


PS. dual master, front disks from a 69 and all small pattern.
Click to expand...
Above discussions cover front drums.
If the 8.75 came complete from a '69 A-body, the rear drums are nominally 10 x 1.75". Shoe frames should be stamped 331 and the adjuster hardware should be the '69 up type.
 
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