Brian,
You are correct...1991 was 487 and 488. The clips we showed were abbreviated ones and I believe you only see both engines one time. In 1993 they used 3, and also in 1995 and 1997. Not sure, but I think they only used 2 in 1994 since basically only a portion of that Windy Point drift was the only major plowing to be done.
I was there in 1991, 1993 and 1997. My brother was there in 1991, 1993, 1994, and 1995. So between the two of us we have them all covered after 1983!!
Greg
link to snow plow videos.
[
www.gregschollvideo.com]