It's not as egregious as the first Harry Potter book or anything, but there are a few places that H2G2 has some wording changes.
But actually there is a whole separate addition to the American version of Life, the Universe, and Everything from the original. When they're at the flying party, the one screenwriter who won the award for "Most Gratuitous Use of the Word 'F***' in a Serious Screenplay", in the American version instead won the award for "...Use of the Word 'Belgium'...". It then goes into a whole explanation about how 'Belgium' is the most offensive word in the galaxy (which was taken from another part of the radio series), with Arthur trying to figure it out but being clueless as usual.
Some people seemed to think it was some kind of American censorship thing, though the American version of So Long, and Thanks for All the Fish contains the aforementioned 'f'-word unedited, so I don't know. But the 'Belgium' sequence is pretty funny, so I think it worked out ok, whatever the reasoning.