Also the input shaft is different, The kadett rallye has a 2 bolt flange that is mounted to steel spring shims(circle shaped) and very thin like the headlight shims. It is mounted to this ring with two rivets. Then another flange is mounted to the steel circle. The GT has a U-joint here. I have an NOS input for the Kadett-although there is no metal ring attached(they call these rag joints on muscle cars as their's were similar, but used belted rubber as the ring to flex and isolate instead of the steel ring like in the kadett)
If you need pics-I could get some-too bad I torched mine on accident
Keith