If I may venture a guess, the original poster was discussing the use of the 5T suspension on the 2.5T axles.
And yes, the frames are the same width. I can think of a few issues interfacing the 5T bogies and the 2.5T axles:
1. The tapered studs on the dogbones may be thicker on the 5T, precluding use with the 2.5T axle brackets.
2. I would guess that the leafs are also incompatible, but that's little more than a hunch.
3. If you are forced into using the 5T axle brackets, the axle [square] tubes are different dimensions. The 5T is a hair under 5", and the 2.5T axle is (as memory serves me) 4" on a side.
If you can solve 1 and 2, then you could do that.
That said, swapping those bogies is probably a major, major hassle, even with a crane to help. I would wager that lengthening the 6 dogbones each by a few inches, along with adding a leaf, would be much easier.