custom item displays and componets

so for optimizing im try to turn my armorstands into item displays but i dont know how to use the custom model data componet with it
heres the command and i can give the resource pack if need be but plz help
/summon block_display ~-0.5 ~-0.5 ~-0.5 {Passengers:[{id:"minecraft:item_display",item:{id:"minecraft:allay_spawn_egg",Count:1},item_display:"head",transformation:[1.0000f,0.0000f,0.0000f,0.4375f,0.0000f,1.0000f,0.0000f,1.3750f,0.0000f,0.0000f,1.0000f,0.0000f,0.0000f,0.0000f,0.0000f,1.0000f],"minecraft:custom_model_data":1}]}