Those are not 10" drum wheel cylinders.

Get a copy of the FSM, in the brake section it is clearly shown. http://www.mymopar.com/index.php?pid=109

The Raybestos ones match the FSM. You either do not have 10" front drums or someone put wheel cylinders out of a 9" drum in there.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.