Unlike newer FWD cars (which is what it sounds like you were more familiar with) the GN didnt have a removable cradle assembly the engine sat in. Its just a big plain crossmember that attached to the two full-length frame rails the body rests on. Any rwd g-body car from the 80s, ie cutlass, regal, or grand prix with 3.8 v6 would be perfect match, a monte carlo or any of the above with a 307 v8 would work too but just need to get the frame pads for the engine mounts from another car after....