1994 GMC Suburban Owner's Manual - Page 86

Parking Your Vehicle (Manual Transmission Models Only) Before you get outof your vehicle, put your manual transmission in "R" (Reverse), turn off the engine, and firmly apply the parking brake . If you have four-wheel drive, be sure your transfer case is in a drive gear. Your vehicle could roll if it isn't. If you are parking on a hill, or if your pulling a trailer, see "Parking on Hills" or "Towing a Trailer" in the Index. Parking Over Things That Burn I A CAUTION: Things that can burn could touch hot exhaust parts your under vehicle and ignite. Don't park over papers, leaves, dry grass or other things that can burn. 2-30