GMC 1993 Safari Owner's Manual page 308

Service & Appearance Care
Service Replacement Part and Filter
Recommendations Table
Engine
Cap
Filter
Plugs
Valve Cleaner Filter
(VIN)
Radiator Fuel
Spark*
PCV
Air Oil
4.3L (Z)
PF51 A773C
*Use copper-cored resistor type spark plugs.
RC36 GF481 .CR43T A1163C PF51
4.3L (W)
RC36 GF481 .CR43TS CV789C
Filter
TO005
6-70