Because new guides cover the things that have been covered time and time again, I can't recall any that have different stats for weights and carry weight of cars and items in game.
That being said, even redoing an old and popular thread with added and most important updated information on them could be the way to go, just make sure any material you borrow from other people just give them credit at the end, noone on the server minds if people copy their stuff as long as they given credit.
You said it yourself that the information on that page is outdated even if your post only helps one or two people surely thats better than worrying that noone will appreciate the effort you put in.