Custom brake brackets

[Mutt's37Buick]

I'm currently planning on buying CPP 30101 drop spindles for my project , but I want to adapt it to work with 12" brakes and rotors with my donor car ('95 Roadmaster).
I'll need to have a sleeve machined to adapt the bearings and need to have a custom bracket machined (or laser cut) to hold the calibers.
1) Has anyone bought CPP brake brackets 5870DBK (see attached) that can tell me the thickness of these plates?
2) Does anyone know what metal they are made from (I'm guessing zinc plated steel)?
3) Does anyone know if a part like this would need to be heat treated?
Thanks for your help

 

[mopar4life]

1 no idea
2 1018 or a36 (mild steel hot rolled)
3 no. heat treating is done mainly to add wear resistance.

sounds like you need to befriend a machinist.

 

[Dirtyrat]

I'm making my rear brackets, they will be mild steel CRS 1008-1010, 3/8" Thick just like most of the kits I see for this same issue I'm dealing with...