[TR] TR head rebuild

[Randall]

> They pressure tested it and say there
> is a very tiny leak around the edge of the aluminum plug that is located
> under the valve cover in the center of the engine 

I believe the racers remove the original plug (which is cast in place), and
then tap the hole for a pipe plug or similar.  The leak very likely
indicates that the plug is corroded from below, so I wouldn't just ignore
the problem.

Randall