That would get expensive real quick. Not only do you have to swap out the motor, you’ll need a whole lot more. New trans, new shift linkage, new mounts, new axles, new subframe, everything in the engine bay has to be swapped around, new ecu (which you can’t use without the key, so you’ll have to get an obd1 with a base map if someone is willing to make it for you) upgraded brakes, the cluster has some differences so expect things to not work, you’ll probably have crazy codes so you’ll be in limp mode (presumably). You’ll probably need custom axles as everything the j35 came in is way wider than the cg6. New fuel pump, and probably other things I forgot to mention. You need to have a REALLY good handle on wiring to even begin the process. Then you’ll need to find a shop to make those custom axles for you and you’ll definitely need custom mounts and a grinded subframe. Also it may not even fit between the chassis rails so expect to have to work around that. You probably won’t be able to close the hood and other minor things lol.