Yes temporary only. If you look at the stock ones. Note the smooth inner diameter for non-turbulent airflow. And, you'll also see there is a step at the carb end to match the carb inner diameter to the coupler inner diameter?
Turbulent air flow causes rather odd things to happen while mixing fuel with it at different air speeds. Carbs don't behave predictably with turbulent airflow in the throats.
Pretty good post apocalyptic fix through.
Cheers,