Not all 1g's had 4 bolt rears. IIRC, only 94's had 4 bolt rears and all the others had 3 bolt rears. Whereas, all 2g's include a 4 bolt rear. As far as being interchangeable, I don't believe they are. They run a different spline count between the two generations. Of course I could be wrong and somebody else may know the facts like the back of their hand...
(cough)Kevin(cough)
