Oh man, don't buy parts based on ideas that have popped into my head. I'm dead wrong most of the time... I do know for a fact that the larger bushing is WAY too big...
One thing I can think of though is the Chevette bearing might be a loose fit inside the Opel bushing.
My solution to the whole damn thing is a 4.10:1 S10 axle, sitting in my backyard, just waiting for me to get some free time.