I’m not much of a builder so you’ll have to pardon me if this seems like a silly question. Lets say I have parts that I want to rotate but need to be smoothly aligned with the others. How would you do this?
Heres the same issue I’m having but at the front of the train. It all needs to be connected but if I try to use plugins like GapFill or just resizing with the smallest setting it will end up looking uneven and parts will be sticking out.
Maybe try this plugin. 
i think the best way to filling the gaps by using this plugin:
and you also can use this plugin as well
so I hope both of this plugin help you with the gap situation and always see you next time seeya
People linking gapfill even though he said it does not work. I suggest using a very small increment (such as .1) For the first pic, just pull back the blue and move the red up. I’m not sure how the second pic would work but my suggestion is that you should try to insert a block between the wedges and part. If not, try to negate off the sides using a stretched brick and pushing them into the part. my disc is asher #3785 if you’re confused no spaces no caps