To my knowledge they do not make a mopar rally wheel that wide! I know you can buy them from wheel vintique and others but I never heard of a stock 8" mopar rally wheel.Also 4" wheels are for the early darts,valiants etc.The later model mopars in 70 I believe were the 5 on 4.5 bolt pattern and I believe the widest those were made were 7" never heard of any 8" wheels.But I could be wrong.Try these links
www.Texasacres.com
www.moparts.com and go to links area and there will be several sites
Bobby Dodson