I just finished adj the valves and had an issue with the insulation in the back of the engine. When I pulled the backmost valve cover bolt I tore the face of the insulation. I didn't think much of it until I removed the valve cover and noticed bits of insulation all over the valve train in the back. Had to shop vac it up. So here's the tip, put a piece of cardboard in the back before you do any valve cover removal. This will keep you from tearing the insulation and keep the dirt that's on the insulation from falling onto the valve train.
WOT
WOT