Hi Ari,
If Steve found the info on the 385 it's probably the same for the 374.
To give you an idea, I have some pictures of a Sennebogen lattice boom crane.
This one has a sliding track, but it's also constructed to use for a longer time.
Here you see it in transport situation, and the slides are sticking out a bit:
But when it is in use some additional steel blocks are screwed to the side to make the carriage wider. These blocks weigh a few hundred kilo's and there are I believe 9 strong bolts. This is not a daily exercise, but when you move the crane every few months, it's happening maybe 3 or 4 times a year, something you can overcome.
A closup from the block:
And sometimes they don't even bother to take them off!!
If you already have a permit for the transport, better give the dimensions with the blocks:
Just to give you an impression how it's done with a crane. This same type is also delivered with removable tracks, they can lift themselves up and take the tracks completely off:
This all is off course different from an excavator, but you see what type of solutions there are for transporting large equipment.