I bagged 8044 as well. The BN patch was unique, so it stuck out in my mind. Denver, CO: Cheyenne, WY:
I don't think that cab has been modified. If you compare the two engines (both are GP39-2s) the cabs seems to have identical positions in relation to the front trucks. BNSF 2941 is a late production model, after EMD had relocated the prime mover (and with it everything else in front of it) 3 feet to the rear. This leaves 3 feet of blank metal behind the cab, providing quite a different look.
This makes sense since there is more room right behind the cab, just never noticed it before. Must be the angle of the shot?
That 8630 is a solid catch! This is BNSF, but it's hard to tell. From beside the old GN yard in Minot, ND, sunset on the flanks of some BNSF hoppers:
Speeding along somewhere on US Highway 87 in NE New Mexico or North Texas, a string of parked cars loaded with old ties. Siding on the old Denver & Fort Worth line.