When doing replacement or upgrading on 1974 – 1983 Fiat X-1/9, the bulb size guide is necessary for you to take the reference.

1974 – 1983 Fiat X-1/9 Bulb Size Guide
High Beam and Low Beam Headlight	1974 – 1983	6014
Back Up Light	1980	1073
	1974 – 1979	1156
Brake	1981 – 1983	1156
	1974 – 1980	1157
Front Side Marker	1974 – 1979, 1981 – 1983	194
	1980	57
Front Turn Signal	1974 – 1983	1157
License Plate	1979, 1981 – 1983	67
	1974 – 1978, 1980	89
Parking Light	1974 – 1983	1157
Rear Side Marker	1974 – 1979, 1981 – 1983	194
	1980	57
Rear Turn Signal	1974 – 1983	1156
Tail Light	1974 – 1980	1157
	1981 – 1983	67