Eliminating the throttle shaft will slightly increase the open area of the throttle body. This should result in more airflow, which would really benefit you at WOT, albeit slightly.

On a K-jet engine, the fuel flow to the injectors is metered by the fuel distributor, which measures the air flow and matches the fuel accordingly.

While you will have slightly less restriction to air flow at mid-throttle settings, this only means that you'll open the throttle slightly less to achieve the desired power (and resulting speed) for the driving situation.

Your mixture should not be affected.

--
Don Foster (near Cape Cod, MA)