Neither car is capable of a monster motor swap, and neither is that great of a choice. If you want a project car, get a 5.0 mustang. They have 10 times the potential of either of those, are just as cheap to mod, and are more receptive to mods. CRXs and civics were made as slow family cars. Its extremely difficult to make them anything but that. Its fairly easy to buy a 5.0 mustang that runs 11s for under 5 grand.