Mushy brakes 4 life...

72bluNblu said
Checking back into this one with some measurements from one of my 11x2.5" brake set ups.

From the drum, inside friction surface
View attachment 1715141350

Depth. I know I show the tape measure here, but I also measured with a set of calipers- 4.46" to the outside
View attachment 1715141348

This where it gets a little more interesting. This is a set of Dr. Diff BBP axles in a stock A-body 8 3/4 housing, using tapered bearings.
That measurement is 2.3", also checked with calipers. Now, that's with tapered bearings and this is the passenger side, but these brakes work so...
View attachment 1715141349

I think this is the measurement you really need to take. Face of the axle to the outer lip of the backing plate. The square is in tenths on the side being used, FYI, so, this is about 3.45". That's off the mounting surface, not the register.
View attachment 1715141351

And last, in the thread where you ID'd the backing plates I never saw a diameter of the backing plates posted. Did you measure it? The 11x2.5" backing plates are ~12" in diameter measured to the outside edges.

Thank you very much for taking the time to reply and try to help me sort this. I really appreciate it. The car is at my buddies shop, as he has heat and mine doesn’t. Anyway. I went today to grab some measurements for you all.

1- backing plates are 12” OD
2- new drums were exact to my old OEM
3- If i remember( left my notes) I am 3.3” from the lip of the plate to my flange. After measuring the drum from the flange side down inside the recess for the plate... I would need 3.4”. That gives the .100” that the mock up washers behind the drum also clarified.
4- the shoes fit perfect inside the drums. I removed them and verified that.
5- I confirmed my axle to backing plate depth is correct up against what dr diff said it should be.

I guess I have 2 choices here... well practical choices. I could
a- use some .190” steel wheel spacer shims I have in the race car stash between the drum and the axle flange.
B- take a chance and buy another set of “ 11x2.5” backing plates.
c- have the drum machined. I don’t want to do this in case I’m on a trip and need a drum.
D- grind .100” off the plate. This is messy and time consuming.