[Ironhorse]

Guys I am in totally new territory here for this old school shade tree mech. Just recently purchased a new to us 2005 Tahoe Z71 with the 5.3 V8. Think that classifies it as an LS1 but not sure?

Have always ran Quaker State 10W30 in vehicles changing with a WIX filter every 3000 miles. When in doubt on a used vehicle still always used the QS with no problems. When we bought the '05 all we were told is it was "full synthetic Dexos 1 oil" which I have found out is for gas engines, the Dexos 2 being for diesel. Pretty much the end of my knowledge there. No old oil change stickers found anywhere on the Tahoe so.......? Owner's manual says use 5W30 so am thinking just a QS 5W30 and a WiX filter since do not know the original brand used. Am I good here or ......?