Traincraft, railcraft, buildcraft and forestry i use other mods but they aren't big mods like dynamic lights and NEI so i didn't install them while trying to update. All of them lastest 1.7.10 version and forge 1.7.10
if you want your world to be playeable again you must prune all chunks that contains blocks from 1.6.4 mods, but that may wipe out all your buildings so i recommend you to continue on 1.6.4 or move to 1.10.2
the problem is that some mods i use aren't aviable on 1.10.2...
Sucess i had to load the world in vanilla 1.7.10 and all the modded blocks/items dissapeared and i had to readd them in creative only a week long but just some minor tweaks and is doable if somebody needs to update a modding world and it doesn't work right away you can try this