This kind of post is priceless..  thanks for giving us a bit of history and right to the point.
back in the day they did have the time to work on stuff like this.

Joe
1600 single port bug
1.9l bus

-----Original Message-----
>From: Neal Barrentine <vwneal@BLUEMARBLE.NET>
>Sent: Nov 1, 2006 4:27 AM
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: AMC heads (part 2)
>
>I haven't posted to the forum for quite awhile, but was very interested
>in this thread. In 1980 I worked at the Bug Haus in Seattle where one
>could buy a 1600 dual port long block for $369.00 exchange. We sold
>over 365 engines a year, and each one of them had sodium filled exhaust
>valves, three angle valve grinds, and the valves HAD to rotate in the
>guides, which were a bronze/silicone alloy. My job was to pull the
>engine, dismantle and inspect it, clean all the parts, sandblast the
>heads, intake valves and valve covers, press out the valve guides,
>paint the engine tin and valve covers. The owners did the easy work-
>one assembled the rebuilds, and the other did all the machining. If one
>of them was absent, then I got to cover for them. My favorite job was
>running the mill machine, especially fly-cutting heads, but I learned
>the most about physics from grinding the valves and seats. Heat
>transfer is the key to long-lasting heads, and the grind and rotation
>of the valves are the key to heat transfer. I had to throw in my two
>cents, as reading this thread brought back good memories. Have fun,
>Neal
>Neal Barrentine
>Bloomington, Indiana
>1986 GL
>1960 Baja Bug