The 70 speaker grills have all 4 legs the same length. The later years had two legs that were longer. I just cut the two longer legs to fit my 70 dash. Since you aren't sure what year your dash really is, you could get a later year speaker grill and it will either fit, or you will have to shorten two of the legs like I did. No big deal there. I just don't know what would happen if you tried to put a 70 speaker grill on a later year dash.
