You can't just beat the inner apron in. There is an upper brace for the shock that must be modified. To do it right takes about a day. I hope these pics help.
The original stamped steel valve covers don't need as much room. But yes, you really need to beat/move out the inner shock brace.
Troy didn't move the shock brace back much at all on his Hemi Dart clone and it is very tight. But it does work. I've seen him adjust the valves a couple times myself.
