Recommend me a converter for this 273 - 727 combo

Give Dynamic converters a call http://dynamicconverters.com/ tell them every ounce of info on your car and let them build a custom converter for you. It will drive normal on the street but when you hit she will flash. Not a off the shelf converter another words. They more than likely will quote you a higher stall so be prepared but they know what they are doing. Like higher on the price also but gas mileage, and the fun factor will pay off in the long run. There is another custom converter company that is always mentioned on here but I cant remember their name. That's what I would do anyways.