Off of either number 1 or number 4, depending on how you set up the chain and gears. Sending you the info right from the GM manual, this should work for you. If you took the distributor out, we may have to bring it up to TDC on number 1 cylinder after you get it back together and reset it all, if not this should work for you.
Important: Once the composite engine front cover is removed, DO NOT reinstall the engine front cover. Always install a NEW engine front cover.
Important: Be sure to align the camshaft and the crankshaft sprocket alignment marks.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
Tighten Tighten the camshaft sprocket bolts to 25 N·m (18 lb ft).