Brake cylinder shape doesn't match drum mounting plate

[ktneifert09]

I got some front brake cylinders from O'Reilly. I threw them in a box until I got around to doing the front brakes.  Pulled them out and realized that the cylinders that came off the car have a rectangular shape to go through a rectangular cut out in the mounting plate and the ones I got have an oval shape. Looked all over the web, Summit, etc. and everything I can find pictures of has the oval shape.  Does anybody have any insight into what the heck I should do (besides switch to front disk which is in the eventual plan).  The car is going to go into storage for a while and I want to get the front wheels back together so I can roll it and stop it.  Thanks for any help!

[John_Kunkel]

Been in that exact same situation, never did figure what years were what so I just changed the backing plates.

[ktneifert09]

Interesting - backing plates differ.  What a hassle.  That's helpful.

[MrSnicks]

Are you sure you got the correct wheel cylinders?  Front instead of rear?

Patrick

[68 RT]

11 inch and 10 inch are diffrent wheel cyl.

[John_Kunkel]

Drum diameter doesn't matter, there are differences even in the same size backing plate.