We had not travelled many days before/when...

[Tan Elaine]

We had not travelled for many days before/when we encountered many unexpected obstacles like thunderstorms.

Can I use either boldfaced word? If yes, is there a difference in meaning?

Thanks.

[5jj]

I think that we can use both, without any difference in meaning. I don't like 'like' used in this way, though I am probably in the minority. I'd write;

We had not travelled for many days before/when we encountered many unexpected obstacles, such as thunderstorms.