Hi- I have put together another of my Big Brake Kits...: This will fit all Opels, 68-75. Manta/Ascona, Kadett and GT... The original front rotors were 9.4 or 9.6" (75 only), my kit is 10.25" in diameter, Original thickness was 11mm (7/16") or 12.5mm (1/2") thick (75 only), my kit uses 1" thick rotors. Originals were solid rotors, my kit uses Vented! rotors. The brake calipers have 52mm pistons, the originals were 48mm. The difference in braking power, modulation, and durability is real. You will be impressed! The kit includes New Bendix Semi-Metallic Brake Pads, New Wagner Brake Hoses, 2 Raybestos Remanufactured 52mm Brake Calipers, and 2 good, Used!, in-spec Brake Rotors. Ideally your rear brakes should be overhauled or in good! operating condition to compliment the improved front brakes. BTW- you need 14 or 15" Rims. Some 13" rims will clear the calipers, but it varies with the rim....Call me with questions! The cost is $300 for the whole kit, plus UPS/FedEx/USPS Shipping to you. Ernie 561-371-9246