i swapped out a 2.2 for a 2.3HO in my 1991 cavalier. since you are using a different tranny, you need the axles that fit the tranny. the ends of the axles that fit into the hub are the same. although the info will be slightly different for you since you are looking to swap in a 2.4 into a 3rd gen cavalier, you should look in our FAQs for a thread i wrote about swapping a 2.3HO into a 2nd gen cavalier. most all the info will still apply to you, even though yours is a 96 model. you need to find a donor car, and get everything under the hood to make the swap complete. motor, mounts, wiring, tranny, axles, shift cables, etc etc. your car was bolted together. it can be unbolted to install new parts from a Z24.
"What are we going to do tonight?"
"The same thing we do every night. Try to make the SVC go faster!"