Engine, 4.8L L6, 1 barrel

Years 1983–86 Models 1 Factory citations 4

Also documented for Chevrolet

Documented applications

Sierra — Square body (1983–1991)

1983–1986 Factory-verified

shared platform code; cited from the square-body C/K pickup kits; the option pages list the 4.8 liter (292 cu in) 1 barrel L6 for heavy chassis and 30 series trucks; 1987 is left out: its value-features page calls the 4.8L L6 discontinued while the February 1987 power team page still lists it

GM Heritage factory kit — 1983 Chevrolet Truck, p.15.
GM Heritage factory kit — 1984 Chevrolet Truck, p.23.
GM Heritage factory kit — 1985 Chevrolet Truck, p.23.
GM Heritage factory kit — 1986 Chevrolet Truck, p.166.

This page aggregates every documented appearance of L25 in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.