1964 C10 Choke

[akqj9]

The choke on my 1964 C-10 is very hard to pull. If I unhook the cable from the carb it slides freely so the cable is fine. The problem is an arm that rubs very hard on the choke cam. It rubs hard because the throttle return spring controls the pressure. What does this arm do? Is it really needed? It only seems to move the throttle a little bit when the choke comes on. I'm not sure this is the stock carb. I have a 250 straight 6.