The motor mounts, trans bolt holes etc.. are all the same for the AMC v-8's. The intakes, valve covers, oil pan, pulleys, timing chain cover are all the same. Not sure about th harmonic balancer and flex plate. My memory fails me on that, but you can look at the part numbers in a 4WD Hardware bookk to see if they are different.
The heads and block are not interchangeable (yes you can bolt them up but that changes the compression).