Gavin,
since the proving grounds are not there any more...well FORD APG, I can tell you we saw in 2005, the Future ST "at that time" in action on that very course it was at a distance but not that far away. It was in disguised, dressed up as a Zebra. Actually it was very kewl paint skeem, black and white striped front end and black on the bed.
Our guide could not and would not admit to us what it was...but did say...look to your left and you will see something of interest. They arranged for us to see that ST without saying it or letting on that it was an ST, but we knew.
Let me tell you, Todays ST suspension on stock shocks can take that course with EASE.
Our guide did say that our ST's at that time ALL St's were tested the same as the F150.
I don't know how Gen 1's did it with stock shocks,
I can tell you that Ford tested (at the time we were there) up to 2008 at that proving grounds facility.
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