I know there is a difference in the width of brake drums (ie ,Sedans,Wagons,& Thunderbirds pre 57  ( 2inch Vs 2.25 inch )) .Is there a difference in diamater between '54 & '56 ??? Was there 10 inch & 11 inch drums ???? A mate  has a 56  Customline chassis fitted with small brake drums . Maybe someone has fitted early Falcon drums at some stage of it's life ???

Lon

yblocksdownunder