[GTJIM]

The occassional Chevette part can be interchanged with Kadett 'B' parts - like a whole diff and I think the wheel bearings.
One question: "Are you talking about 'English' or 'American' Chevettes?" - they are different.
I have used 1256cc English Chevette intake and exhaust valves (but there are two types and only one of them can be made to fit) plus 1159cc pistons in a Kadett 'B' 1.1Litre motor but most everything else is different - similar, but enough different so they do not fit - Imperial threads instead of Metric ones on such things as con rod bolts, for instance. Have not tried to completely interchange con rods though so Chevette con rod bearings and rod bolts could be used .......
The Opel 1.0/1.1/1.2 litre motor has its distributor in a different position than the 1159/1256cc English Chevette motor - so camshafts do not interchange.
I was going to look at gearboxes but concluded that just another 4-speed was better replaced by a Toyota Corolla 5-speed - that 'project' is still pending .....

HTH