when i did this conversion on my old 66 falcon, i swapped the six cylinder bell crank out for the V8 bell crank, and modified the rod that connected the bell crank to the carb to fit. it worked nicely, and is still working as far as i know(sold the car back in 2007).
as for an air cleaner, i used a small diameter, a nine inch, low profile, about 1 1/2" thick, aftermarket air cleaner, i think it was a cal custom one. it BARELY cleared the hood though, so you might consider milling the carb adapter by about 1/2" as needed to add clearance.
another option for throttle linkage is to use a fairmont cable throttle and pedal assembly. you can also pull the head and have it modified for a direct mount carb to gain more hood clearance as well.
also choose your carb adapter wisely. try to avoid those that use the stock one barrel adapter to align the carb. i used one from transadapt that eeliminated the stock carb spacer. vintageinlines has a few different styles of carb adapters available.
the carb i used was a 2100 autolite carb, worked nice,, but the shorter 38/38 weber carb will also gain you hood clearance, and is a good carb to use.