I measure the height of my carbs with a precision slide ruler... or something like that. just make sure your measuring device is accurate enough, and check both sides of each float.
As for the jets, I would simply change them to what they're supposed to be. Don't fart around with the needles if you don't have to. Though, if your jets have been changed, the needles have probably been moved too. If you can see the slot that the clips are in on your needles, And they're at stock height, leave them alone for now.
First thing is first though, Clean you carbs. Clean them well. Learn the routing for all the little orifices. Make sure they all have something coming out the other end. Very important you do this before playing around with anything else.