Those bell cranks were designed to get better throttle control. They were a pain and Ford left them out later. You would be better off replacing the bell crank with the adjustable link like the one in Airmapper's photo. I just took the little throttle ball off the stock 2bbl carb and bolted it right up to the Edelbrock carb. That adjustable link just snaps on the ball. Real clean!
Everyone has an opinion, so here's mine.
"Those" bellcranks were supposed to compensate for the rotation of the engine as it torques on the motor mounts. My Bronco did not have all that extra linkage and had just the one straight link, like Airmapper. But I used to get in to a bad "surging" situation when trying to slowly negotiate some object. Give it a little gas, and the engine torques over and results in more throttle than I intended. Let off the gas, the engine rocks back in place, and I get less throttle than I wanted! Over and over... !!!
Said screw it and installed a throttle cable, (Lokar) and never had another problem. Easy installation and no more surging. Still can't drive, but that's one less problem.