If you have factory 66 seats then they will not have a release lever and if you have factory tracks then the front part of the tracks have a closed eyelet that goes over the stud that holds the seat down.
If you have 67 seats then you WILL a have a release lever on the back,upper part of the seat. The front part of the tracks will have an OPEN toe to slide onto the front stud.
So...66 seats have no release lever and CLOSED track front holes and 67 HAVE the release lever on the back, upper part of seat and OPEN toes on the front of the tracks. IF every thing is factory Nova seats/tracks. Also the backs of the seats are metal...not plastic.