[GTJIM]

Hello in Norway!
I have a 1967 Kadett Rallye 1.1L and it has discs on the front from the factory,
Looked at fitting later 1.9L Kadett/GT discs but they have a different caliper mounting size.
I think the Kadett 1.1L drum brakes have a different spindle to the disc brake suspension. Different numbers in the Parts Book.
You may be able to fit front discs by changing to the disc brake front spindles (or "knuckle" as Opel calls it) complete with the calipers from a later Kadett or GT. Possibly the complete front suspension from a later Kadett (1967-73) with disc brakes.
Any front disc/hub from 1967-73 for a Kadett/GT/Manta will fit on to the disc brake spindle but only the correct caliper for the particular spindle will fit.
HTH