On reddit there's a post about the running time of all the movies, both US and Japanese run times. The Showa series had theatrical releases in the US, which were usually edited in some manner. So it makes sense when most of those have different times. But Heisei and Millennium movies were barely touched, aside from G'84 and G2K (again theatrical releases with edits) to my understanding. I can kind of understand a few minute difference in the Heisei series if they chop the credits off their count of the time, which I think Sony did for most of the DVD/Bluray releases of the movies.
But two stick in my craw.
Godzilla X Megaguirus - Japanese 105 minutes, US 88 minutes
GMK - Japanese 105 minutes, US 85 minutes
Twenty minute difference. Like is the Japanese cut counting the Hello Kitty short that went before the movie in the theater? Because if there are cuts of GMK and Megaguirus that are 20 minutes longer, I really want to see them.