Question About Physics Mod Inconsistencies

Alright, so some of you might know that I've been playing with diesel locomotive physics mods for the last month or so.
I've experienced an odd issue where identical physics mods will work on one edition of the ES44AC / SD70ACe, but not another.
For instance, my ES44AC mods I have applied to the Kuju ES44ACs and BNSF ES44ACs (Marias Pass and Stevens Pass) work, but when I try to apply the exact changes to the CSX ES44AH, NS Heritage ES44ACs, Sherman Hill ES44AC, and the CP ES44AC, it renders the locomotive inoperable; the locomotives will refuse to load in quick drive, and when I try to drop them into a route via the scenario editor, they will actually disappear from the selection menu all together.
So my question is does anyone know what is going on here? I am applying the exact same changes across the board, so it doesn't make sense to me that it would work for some locomotives, and "break" others. It's a bit frustrating.
Thanks in advance.
I've experienced an odd issue where identical physics mods will work on one edition of the ES44AC / SD70ACe, but not another.
For instance, my ES44AC mods I have applied to the Kuju ES44ACs and BNSF ES44ACs (Marias Pass and Stevens Pass) work, but when I try to apply the exact changes to the CSX ES44AH, NS Heritage ES44ACs, Sherman Hill ES44AC, and the CP ES44AC, it renders the locomotive inoperable; the locomotives will refuse to load in quick drive, and when I try to drop them into a route via the scenario editor, they will actually disappear from the selection menu all together.
So my question is does anyone know what is going on here? I am applying the exact same changes across the board, so it doesn't make sense to me that it would work for some locomotives, and "break" others. It's a bit frustrating.

Thanks in advance.
