Recommend me a converter for this 273 - 727 combo

I'm going to suggest a 904 trans swap. The 727 just doesn't get the horses to the pavement like the 904 does.
Difference may be in the gear ratio. i really dont know.
I think a stall converter with that 727 still wont make you happy.

Redfish, I'm with you on this. I can't see any real advantage with a 273 street engine needing a 727.