Reply to "Emission Label Missing?"

I really don't think there ever was one. The fender panels look undisturbed.(spots welds and all). Anyway, since the car came from Colorado, the owner had the timing advanced for his thin air(6500 altitude). What should I set the timing around? Here in Palmdale we around 2300 ft. altitude, engine mostly stock, edelbrock, 600cfm holley, aftermarket headers. I noticed the engine sometimes sounds like its advanced too far when cranking, you know, struggles at times rotating? Then lights and the fun begins. Runs like it likes it new home. I'm getting more wrinkles from smiling so much!