Yeah I had that size on the back of my stock bullitt wheels. The manufacture doesnt recomend them but they fit fine. I liked the wider look out back. You have to keep a lot of air (max on side of tire) in them to keep the outsides from wearing out faster though.
They will fit, but they will bulge a lot. Depending on the brand of tire and how much sidewall flex they have, your handling may suffer slightly due to rolling over on the sidewalls.
Typically on an 8" wide rim, 245 is the max recommended width.
But a few guys have gone with 275...it looks mean.