Recommend me a converter for this 273 - 727 combo

with what you have going for a combo....I would suggest something like a TCI sizzler stall converter (thats what I am running).

I think its advertised around a 2200-2500 stall

and the price was pretty good on it ( I think i paid around $300.00 for mine).
I was thinking the same thing around 2200, but I know it can be a hard time trying to get converters for the small journal.