TQ opinions/question

Here's my issue. I've built a 360 Magnum like the mild magnum build here on this site. I'll be starting the install of it in the next few weeks.

My car is a 67 Dart with its original 904 with 18 spline and its original 273. Performance torque converters for this are either non existent or insanely expensive. I have an 8 3/4 that I'll also be putting in. I was planning on using 3.55 gears in the rear and a Transgo in the transmission with the stock converter. Would 3.73's work better with the stock converter?

The car won't be used for the strip, just kind of a hot street deal. Will my combination work okay until I get another Trans that has the later spine so I can get a higher stall converter later on?

Thanks,

Doug