Here we have a "Magic Head " from Mike Melde,I will make one of these soon!
With o-ring sealing and removed attchment...
And runs with a flat-top piston which is lighter and gives more RPM.
I take it thet the wires are coming from a solid state temperature sender?
I have looked into getting one of those as they are avaliable in M6 thread which if I remember right is the same as the normal air bleed screw at the top of the head.
Most other temperature senders have a huge thread (1/8 NPT) which would need another hole in the head.