"http://www.aerospacecomponents.com/pro_street_kits.htm"
Actually, the site doesn't state two piece solid aluminum. It does describe an aluminum hub and aluminum hub adaptor. There is no mention of the rotor material. All it states about the rotor is that they are cast and do have vanes in them. They note that it is for a street application. So, I would guess the rotors may be cast iron. Another clue is that they offer a zinc coating for the rotors.
Actually, the site doesn't state two piece solid aluminum. It does describe an aluminum hub and aluminum hub adaptor. There is no mention of the rotor material. All it states about the rotor is that they are cast and do have vanes in them. They note that it is for a street application. So, I would guess the rotors may be cast iron. Another clue is that they offer a zinc coating for the rotors.