Choke assembly

That is the list number for the 600 double pumper. As I recall they usually had the bracket and clamp to allow for the connection of a manual choke cable.
Does your intake have provisions to install a thermostatic choke as in a choke well? The factory iron ones do, but pretty much all of the aftermarket aluminum ones do not have one.
This will play into the direction that you will need to go when looking to add a choke.