Wanted to update this thread, after a lot of research I decided to go with the Borla throttle bodies. My initial impression is they seem to be high quality pieces...time will tell.
Next up was to tackle the linkage and come up with a way to handle the vacuum signal for the map sensor. I purchased Borla's linkage and fabricated this vacuum block so I could bolt the linkage to it.
I also drilled and tapped each runner in the manifold in order to collect vacuum to my plenum.
Next up I had to take the Hall manifold to a machine shop and mill the existing pedestal off as it is not in the center of the manifold. I can only assume the Weber carbs needed an offset linkage. After milling the manifold I made a 1/2 inch aluminum plate to seal the hole in the manifold and provide a place to mount my vacuum block/linkage.
The linkage is now mounted and centered properly. It is solid and seems to operate perfectly.
Next I have to fabricate my own fuel rails...nothing is ever easy on these cars.
