So the good news is, so far the head itself looks great! No cavitation, no cracks. What I found so odd though was the amount of CARBON. ON the exhaust valves it was caked on like about 3/8 inch thick in places. A few years ago (before the floor rusted through) I had replaced the valve seals, rebuilt the injectors, and ran probably 3 cans of purge in pure form through it. Is this level of carbon build normal? Once I get all the valves cleaned I'll start measuring stems and guides and play and such to fidn out what this is going to set me back at my local machine shop. But thought I'd ask what causes so much carbon! I'm hoping it;s not oil seeping down the valve guides! I'd like to just get the valves and seat refinished!