I'm trying to see where the exhaust is vented, as well as if it still provides a thrust augmentation effect like the Merlin/normal Allison exhaust stacks. I know that vs the F-82E that the F/G models were about 4-5 mph slower in level flight, though much (if not most of it) was due to drag from the radar pod. Also, the F-82H was a F/G with the radar equipment removed to be used as an interceptor in Alaska until F-94s and F-89s were able to be issued up there. They didn't carry radar equipment, though all or almost all kept the night fighter exhaust systems and I doubt that they were ever converted into being dual control like the F-82B and E were.
Also, the F-82C/D night fighter development aircraft didn't fly with flame dampened exhaust, since they were Merlin powered and such a thing was never developed for the Merlin powered F-82s