The 3940 is not an equal to the 3400 (it's quite a bit more tractor). The 3940 is a heavier tractor, that could be a plus or a minus depending on your plans. The loader is able to handle more and I would guess lift higher than the 3400. I also think the 3940 is a bigger frame (could be wrong). The 3240, 3540, and 3940 all use the same loader so depending on what your plans are you may want to look at the 3540 as it'll be closer to the 3400 HP wise. If the extra HP is of value to you and you plan on doing plenty of heavy lifting with the loader then you may want to look at the 4240 as well, it's slightly bigger and the loader can lift higher and more.