I'm looking at my Taig right now.

OK so the black headstock is clamped onto a dovetail on the bigger gray block with the rail guide shoes and leadnut. The motor's mounted on the black headstock and appears it would move with it.

So this dovetail is a slide, and the black part of the headstock is at the bottom. In fact there's an extra empty pair of threaded screwholes so it looks like the dovetail could just as well be mounted higher too.

I'm wondering. See right now the collet can touch the table which is further than it could ever need to go (bits have a nonzero length too), with leadscrew and rail travel to spare on the low end. I have a Modular Work Holding Plate raising the low end up further. I've also wondered about the quick change collet system which would raise the lowest height needed as well.

So, I could always use more upper Z-clearance. I will never be able to use this lower end the leadscrew and slides can travel now because that'll put the bit below the table.

Is this meant to be adjustable? Can I just move the black headstock higher on the dovetail, and can the dovetail itself be mounted higher?