I would also remove the half bypass that is just aft the turbine, there's not enough clearance and you may run hot and loose power.
I believe you are referring the heat shield. On My FEJ F-16 I replaced it with one I made out of thin aluminum, which is much more effective. I have about 3/4" to 1" clearance between the shield and the turbine case all around. There is also room for some airflow over the top of the shield.
Joe