Prior to 56 the throttle linkage to the carb was on the right side (sitting in the drivers seat) of the carb. 57 and later it was on the left side. up to 56 had a bell crank that transfered the linkage to the right side that bolted on the back of the manifold, note the two bolt hole mounts on the early manifolds.
Using a 57 and later manifold/carb setup you may be able to just run a rod from the firewall linkage to the carb without the bell crank as long as its not an auto. on trucks I have changed the whole gas pedal linkage assembly to later or earlier style depending which way I was going. my 58F100 I took to Columbus i put the earlier style carb dist, so I had to use a pedal assembly from a 57 or earlier truck.
An easy way to extend the rod is cut it, thread it and tap a piece of break line the correct length to match, add a couple jam nuts and you can adjust the length as needed.

55 Vicky & customline
58 Rack Dump, 55 F350 yard truck, 57 F100
59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?