10 inch backing plates

I have several early A bodies projects, I will call them, as none are exactly finished!!! working on a 66 belvedere I drug home. its a slant car but I will eventually change it over to a big block. it has 10 in drums, I want to get it on the road and drive it to work when I go back to my piddly part time old fart job in the spring!!

question is, I will rebuild the 10 in brakes, but I will later change the k frame and add discs to the bel. BUT, can't I use the 10 in drums stuff ( backing plates out) on one of my early A cars that is a slant with 9 in drums???? 10 in brakes for it will be a step up for now.... thanks