Are you referring to adapting a later large hole crank to accept a small button converter? If so, yes, those are available, but I can't remember who sells them. If you're referring to an early 273 crank that isn't machined for a manual trans pilot bushing, Brewer's has a BEARING assy to do that.
A buddy of mine made me some wedding rings to address the later model register. Basicly if the later model crank is used with an early model torque converter with the smaller hub is used the rings take up the slack.