Two things to note:
Always measure new trucks, not used trucks, as too many things can happen with older or used trucks, least of all being the bushings and pivot cups compress giving them a lower look. Some bushings I have from used trucks are maybe 1 to 1.5 mm squashed down, when compared to the stock new ones. Also hanger wear can change how a truck will look, as well as bent axles.
Also check the angle of the hanger and is it completely level from end to end of axles? Some will sit higher on one side and lower on the other, so this by itself can make some trucks look taller and some look lower, from the same set, just by looking at the right or left. With most trucks, there is going to be a fair bit of difference with this alone, especially if a higher side of a lower truck is sitting at the same height or above the lower side of a taller truck, as I have set up in other pics.
Indy standard = 55 mm tall and I can feel every mm of it for carvy turns when compared to Ace, Venture, Thunder, etc which are all lower, when paired with the same board, same wheels, even same bushings if it comes down to it, but a thin 2 mm rubber riser makes most of those others feel about the same as the Indy standards and I can carve as usual with no wheelbite or at least none that throws me off, the Thunders especially.
Not saying there are not going to be instances where trucks will feel different or have other things going on, but with a lower bottom bushing, a standard Indy truck can feel almost 2 mm lower as well as sitting about even with those others in the 52 to 53 mm height category. The kingpin was a lot closer to the hanger axle part on that set too, which needed a spanner to get to the kingpin as the usual skate tool was too big to get down over it.
Sorry, probably too much useless wooden toy knowledge, but it is fun experimenting and working out a few things like that too, just to feel how different trucks can perform from stock or factory builds.