Why bother, Bruce... those of us on the PRRFAX list are already "true believers" and it would be just preaching to the choir.
Anyways, neither of these locomotives should have held on to the speed record. One serious contender would most certainly be the PRR's class T1. There are documented stories of these locomotives regularly running at 125 mph, with apparently room to spare, and other stories of them reaching at least 135 mph. I personally have heard from the son of a Crestline shop supervisor that when they were shopped it was common to see that the hand on the speed recorder was bent from hitting the stop pin...
Which was set at 130 mph.
Not narrow gauge, but still impressive...