Let my oil get lower than I would like. 4.2 vortec in a 2008 GMC envoy. Sounds like rod berring knock and she drank 4 quarts plus honey. Drove it 3 miles and it stalled at every intersection. I also couldn't use drive, only 1,2,3 gears and then it would stall again slowing down/ stopping. I am keeping this car. I have plans to make it a tbss clone but my main concern right now is if I can take a junk 4.2 trailblazer engine and put it into my envoy to keep her driving for now. Is it plug and play? Or would I need to find a 4.2 from an envoy due to sensors and how **** lines up? Or would I be able to find a block from a trailblazer and switch everything over? I will be doing all the work myself. Looking for cost effectiveness and time.