How imperative is it to trim the headgasket? This is something that didn’t appear to interfere upon assembly of my engine. Also how often should valve lash and rocker torques be checked in a performance application?
Generally the lash won't change, the adjusters won't really move, other things like valves/cam wear, etc...generally we recommend 50-100k mile check of valve lash depending on application. If it's hydraulic lifters you never should need to make adjustments. If your pushrods clear then you don't need to trim them, sometimes the pushrods will touch the head gasket slightly and it can make setting lash accurately a little more challenging.
