Hi Frank,
My reference book states "BN's landmark 350-unit order became the foundation of a BN/BNSF SD70MAC fleet that topped out at 786unit..."
It also states that, "BN 9400-9571 were the onlySD70MACs built without isolated cabs."
and that,
"In March 1995, beginning with BN9572, the isolated cab became standard on the SD70MAC."
Reference information supplied by: LOCOMOTIVES - The Modern Diesel & Electric Reference
by Greg McDonnell
BTW, I have seen, many, many times, both the executives and the heritage painted MACs; working BNSF's four unit coal trains, with two units at the front and two at the rear, coming from and going to Delta Port(Roberts Bank Superport), in southern British Columbia.
They're usually teamed up with GE motive power... ES44ACs and/or AC4400CWs.
Thanks for the pictures.
Rick