Even with the use of the stock thin paper base gasket, the heads will still pull down after the engine has been up to operating temperature. I would not say that Robert has done anything wrong by not re-torquing the heads, but as I served my time as a mechanic as did Bill and several others on here, we were taught to re torque cylinder heads on cars and other vehicles. It is one of the tricks of the trade that almost certainly saves the premature failure of head gaskets on at least some vehicles. It is a habit that i still use and will always use. You could carry out the practice of over-torquing the head nuts like Terry Prince does, as he pulls them down to 45 Lb's plus, his theory that once the bike/engine leaves his shop that the owners will never re-torque the heads again. I don't subscribe to that practice at all, it is a near guaranty of failure, the cylinder studs and columns through the head and the barrel are not designed to take that much load, it will either pull the threads from the crankcase, and/or damage the head. Just my views..............