Any 1978-87 El Camino or GMC Caballero
g-body 1978-1988
No, they will not interchange.
Pretty easy because there was no El Camino SS in 1978.
No
1968-72
From what I understand:1980 & 1981 complete grill with the headlamp bezels will interchange
Any GM A-body AC box from that same body style. That includes the Chevelle, Skylark, and Cutlass.
65 66 and 67 will interchange.
Doors from a 1978-87 El Camino or GMC Caballero
64-65-66-67 chevelle.
187 inches