Thanks for the Input, but both of you have not really contributed anything new for me, or the measurements i specifically asked for.
@swathdiver: we have pretty strict regulations (TÜV), I am aware of the Brembo Option, but ist is not realistic in several ways.
@newdudeI know that all the front calipers from GM are iron, that ist why I asked for measurements to use the rear ones. I Run 8.5x18 oem wheels from the 2kxx Chassis.
I upgraded the rear brakes to the 330mm dual piston ones from the suburban (These calipers are aluminum).
I also checked clearance of the 4-pot ones from the 2019 silverado, but they do not fit my wheels, and the spacers that would be necessary are not TÜV legal.
So I want to use the 330mm Rotors from the rear drum Brake gmt800 silverados, but will try to negate the weight Penalty by using the aluminum calipers.
I am a trained mechanic with two decades of experience with american vehicles, racing, modification and Restoration.
Unfortunately there ist very Limited Access to parts and relevant information in Germany.