The other day I killed my 66 Fastback engine. I did a comp. check on found the #4 cyl lost all comp. I pulled the head and foud a bent exaust valve. I expected much worse! I took it up to the machine shop and had it inspected. It turns out that it was not from floating the valves. I over heated the head and the valve started bonding to the guide, this caused it to hang open until the piston smacked it. He said the head look fairly fresh, and would just need a new guide and valve. Now I just have to fix the running hot thing! I pulled the t-stat out when I first got the car, but it still seemed to have very little flow in the radiator. I'm thinking the impeller blades on the water pump may have rotted off. I have seen this before on cars that have sat a long time. It could also be the radiator, I have a 4 core for it, but I need to get it flushed. I can't wait to fire her back up!!