The lens were fitted in place of the AI23 radar in the “bullet”.
If my memory is correct the bullet also had ballast in to ensure that the correct weight was in the nose. The AI alone weighed 225lbs.
The F1A’s were a lot faster than the squadron F3/F6 models.
TFF pilots would have great fun at the end of the day slowing opening their throttles as a squadron F3/F6 approached and then out running them!

It was a common occurrance to hear over the radio a frustrated F3/F6 pilot
cursing the TFF pilot.