There are character editors around that can increase carry weight, but not "unlimited". I would suspect that there is a maximum value to which you can modify it.
F2SE.exe can do it (best to mod the bonus stats, not the standard stats btw since those derivative stats are usually recomputed when you load a game).
Bad people! Naughty, naughty cheaters! Use your meat shields, er, I mean companions as pack mules like everyone else. In FO1 they have no weight limits. In FO2 you have a car trunk and can stuff your lackeys into powered armor so they can carry more.