The 1974 nova is a uni-body /subframed car. It is also a rear steer car. In 1975 Chev went to a front steer and is about 4" wider than the 68-74 Nova. Somebody will correct me if wrong. Here is a link for front and rear end widths:
http://50chevy.freeservers.com/Suspension_Widths.html#Suspension


Always get a 2nd opinion, especially if I am the source of the 1st opinion.