Goo stock 20x8 have an offset of 56.4mm. As dcorn said the OEM SRT wheels have an offset of 50mm. As someone sent me a pic with that stamped into the wheel. Not exactly sure what year that wheel was though. But it was fairly new. A very good wheel reference calculation site is Rimsntires. Com there graphics are a little better than some of the other sites I've seen. Hope this helps you.