[Morris42563]

Changed valve cover gasket and now wont run was running when I changed it

 

[SlammedRanger]

Anytime you change the valve cover gasket you have to re-adjust the valve tappets. The reason you have to do this is because the rocker arms are in the valve cover and anytime its removed chances are you dont get it in the exact same spot. The gasket actually works as a shim to an extent and also could be a slightly different thickness then the one you removed aswell. Welcome to the forums!