Help! Master cyclinder ID

[rooster]

I seen these Masters and picked them up cheap dont know what there for. Was hoping thay may fit the 49 Chevy to support the pedals from under the floor, then mount a newer master cyclinder from behind using a longer shaft that would go threw the junker to operate it. Still dont have Gregs car home yet to compare any differences. Both cyclinder are Delco! Anyone know what there for?

[enjenjo]

The front one is a 41 to 48 Chevy car. The back one may be a Buick, but I'm not sure.

[rooster]

Ok the one on the left is 41-48 chevy car! It has a 7/8 bore. The one on the right has a 1" bore  and different linkage ends than the other. Anybody Know?