I purchased a temperature gauge kit for outboard motors (#58862P comes with sender and "z" bracket) to install on my 1973 Evinrude 135. The included instructions only discuss motors far newer than mine. I do however, understand the "z" bracket install, with one exception. Should I install this bracket under a head bolt, or under a head cover bolt? I've spent a good deal of time researching this, and just about everything I've read says mount under head bolt. My head bolts would not offer any surface for sender contact on the head if the "z" bracket were used, but would offer plenty of surface if mounted on the head cover. I would sure appreciate a picture from anyone who is actually mounting the assembly under a head bolt. While on the subject, I'm thinking that the ideal area to mount this type of sender is high up on #1 cylinder. Any thoughts on that as well would be appreciated. Geezer.