Made this tram bar a few moths ago and it worked out great for me so I thought I would share.
I never had a problem tramming front and back, using aluminum foil. But side to side always seemed raise my blood pressure and I could never quite get it good enough. Full disclosure, I’m an ARP. Looked over the HDZ and saw two threaded holes at the bottom of the mounting plate 
tram bar.
HDZ Tram Bar.pdf (24.2 KB)
Made from 6061
I don’t recall the thread size on the plate, they were metric. The set screws were 1/4-20 x 0.75".
Set up was a piece of cake. Loosen the spindle mount and let it drop all the way down it the holes. Bolt the tram bar to the back plate with Loctite. Tram front to back first. When tramming side to side, use small clamps with rubber feet on top of the mount to the bottom of the tram bar and crank them as tight as you can get them. Adjust the set screws to tram side to side, and once you are spot on you can crank the four mounting screws down.
This is the tramming video I followed.
I run a 2" surfacing bit at 70% step over and can feel no ridges with my fingernails. It may be overkill, but the tram bar worked well for me.
This will fit the first round of HDZs from Carbide 3D. Not sure about the later versions or the original from Beaver. I’m sure with a few mods to the drawing you can make it work.