1996 GMC Safari Owner's Manual - Page 256

NOTICE: When adding coolant it is important that use you DEX-COOL (orange-colored, silicate-free) coolant meetingGM Specification 6277M. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner at 30,000 miles (50 000 km) or24 months, whichever occurs first. GM Engine Coolant Supplement (sealer) (GM Part No. 3634621) with any complete coolant change. If you use this mixture, you don't need to add anything else. -- What toUse Use a mixture of one-half clean water (preferably distilled) and one-half DEX-COOL" (orange-colored, silicate-free) antifreeze that meets GM Specification 6277M, which won't damage aluminum parts. Use Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, can boil before the proper coolant mix will. Your vehicle's coolant warning system is set for the proper coolant With mix. plain water or the wrong mix, your engine could get too hot but you wouldn't get the overheat warning. Your engine could catch fire and or you others could be burned. Use a 50/50 mix of clean water and DEX-COOL (orange-colored, silicate-free) antifreeze. TM 6-26