When buying a used Blazer never assume: 1. Just because there is a PCV Valve, the valve cover has the block off plate removed from the underside, took me 6 months to figure this out!!! 2. There are header gaskets installed. or 3. Just because the wheel weights are on the rim, that they are installed in the proper location. I swear it boggles the mind that some of the things that I have discovered in the last year, that people actually believe to be OK. Tom There are no stupid questions, only stupid people!