ok refresh me

how is this 3rd gen
malibu
64-65 same body wheel base ect 1st gen
66-67 same 2nd gen
68-72 same 3rd gen
73-77 same 4th gen?
monte
70-72 1st gen
73-77 2nd gen
elky
59-60 1st gen
64-65 2nd
66-67 3rd
68-72 4th
73-77 5th

1964-1967 Chevelle/Malibu, Cutlass, & Lemans are considered 1st gen. Even though the body style changed, it carried the same frame structure from 64-67.
1968-1972 is 2nd & 1973-1977 is 3rd. That is where the term comes from.

No it doesn't fit Monte, Elky, Grand Prix, Grand Am, Century, Regal, or Can Am, but it is a generic term to shadow all 73-77 A Bodies sort of like how the Gen 3 & Gen 4 GM engines are all considered LS motors when they aren't.