OK, so it's not quite the same as doing the actual job, but it's a start.

I bought a Howell TBI kit from a fellow AMC-lister some months ago. Not familiar with them, I pulled it out to examine the mounting flange so I have some mental idea of what I gotta do. Since it's for a Jeep it came with a BBD base adapter... and it occurred to me I had a Carter YF to BBD adapter on the shelf... Instant fit! It's not even a kludge -- the throttle body needs to be lifted up 3" or so to clear the valve cover. The engine's carb base hole is smaller than the YF adapter, but there's plenty of metal to severely enlarge the hole and blend it nicely. There is a two-barrel TBI to one-barrel manifold restriction, but flows are low enough it shouldn't matter, and in any case the bore can be increased.