i was given nova springs for my 69 and it sat about 2" too high. when i returned the springs they told me they they were nova springs and they would fit but they have more arch. but camaro springs wouldn't fit a nova so they only stocked nova springs. i've been told this is a common practice
There was an entire family of 15+ springs that were designed to achieve specific ride heights and stiffnesses depending on the vehicle options. Impossible to say whether a random spring will result in the correct ride height without knowing details that you probably don't have access to.