CUCV startup sounds

[cpf240]

Is this located on the back of the left-side cylinder head?

Sorry, I don't remember which one it is, but that sounds right. I'm sure someone will chime in with a confirmation / denial.

I also have a manual glow plug button that was installed before I bought the truck. I have never really used it. Is is possible to have both set up and useable?

Many here have done so. Without knowing how yours is wired in, I can't say for sure. It can be as simple as tapping into the correct wire at the glow plug controller harness and running it through a switch to ground.