Yup its a Nitto Technomic (26.0).
I loosened the allen bolt pretty much all the way before inserting the stem. What happens then is the wedge hits whatever it's hitting and gets stuck even before I tighten the bolt again. Here's a photo of exactly how much the stem makes it in. Does that look like the right amount of insertion possible based on how long the head tube is? Should I just get a shorter stem?