Carter BBD

[78_200_C4]

The adapter on the "foureyedpride" forum looks like it would flow better.
The Sniper EFI small base Rochester version may better choice than the Sniper Jeep version due to throttle lever position.
You would want to raise the carb high enough so the throttle cable clears the valve cover

 

[78_200_C4]

I think that the Vintage Inlines Weber adapter could be enlarged to match an enlarged large log intake bore.
An electric choke Weber 38/38 might be a good choice with each barrel feeding 3 cylinders.
This way there is no chance of the head cracking during 2V conversion after being brazed (if you didn't have a flat D7 head).