I was just wondering if it would work. It seems like its ok to go that size on a 8" wheel when you have a larger sidewall like a 275/60 on a 8" wheel. I was wondering if it would be a problem since the sidewall is much smaller on a 275/40 wheel.

It's not a recommended wheel width but people have done it. The only thing is you may not like the way it looks because the sidewall is rolled and the 275 tire looks crowded on the 8" wheel. I think but I'm not sure there was a thread awhile back that there was some pictures of this combo floating around. Try doing a search.