My quick and dirty reference (the one which most readily
falls to hand) indicates that the F-102 had a max speed
of 825 mph with a J57-P engine,

The F-106 is listed with a max speed of 1,530 mph with the
the same J57-P engine.


The F-106 had the same engine as the F-105, the J-75. Much larger engine

http://www.f-106deltadart.com/j75-motor.htm