oooopppsss heres the pic.

 

If it were me, I'd do like dcairns did on the SS site. He put in two sensor units, one in the intake side of the h/e and one on the output side. Then he mounted a switch right next to his temp gauge to switch between the two temps. Maybe a little overkill, but you would definitely know the difference that your h/e was making.

 

That's an interesting idea....I remember him chronicling the install of his Fluidyne H/E, but don't recall seeing his placement of the temp sensors. Was that a different thread?

EDIT: I think I found the thread and I asked him a couple of questions....thanks Ben.