Mike Rich twin plug heads.
These were a little delayed due to Mike's seat supplier letting him down but they are worth the wait. The old seats had started to loosen so while Mike was at it I had him twin plug them too. The conversion Mike does is different to the usual method in that he uses the boss for the breather port in the head as the new oil inlet point (with some welding and fancy machining of course) and has devised a way to use the original cylinder stud rather than using a socket
head bolt. The stud is shortened slightly and uses a special 10mm 12 point nut so the second plug just clears the nut. Tricky stuff.
This picture was supposed to be at the top.