- 1984 Factory-verified
includes the LJ5 diesel and M75 5 speed; 1TB models only; not with C60 or UA1; the 1985 and 1986 pages print the code as 290 and 790, so those years are not claimed
GM Heritage factory kit — 1984 Chevrolet Chevette, p.31.
Z90 Factory-verified
Documented applications
This page aggregates every documented appearance of Z90 in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.