temp sender question

[scuderia]

I recently put a '68 or so 292 in my 66' that has idiot lights. The sender in the 292 has a single terminal (I'm assuming it came from a truck with gauges or that the later trucks are wired differently). Anyway, I ordered a WT356 with the dual terminals and it's the right diameter for the 292 but it's way too long and won't tread down far enough.
Anyone have any idea what sender might work or how I can wire up the single terminal to work?
Thanks.