big block rockers

I have a set of big block Harland Sharp roller rocker arms. Can these be used with stock Mopar shafts or do I need Harland Sharp ones?

You need Harland shafts. The shafts Harland uses are much harder ( hard chromed) than the stock shafts, as well as have 2 oil holes in them. You are using roller bearing now, so hence the need for the change.