Torque converter size

While we're have a friendly discussion on converters, I have a 68 Dart, 360/727. It was just rebuilt 1000 miles ago by the previous owner, but for cruise nights with a very mild cam. Stock bottom end, j heads with 202's, stock 340 manifolds edelbrock 1406 600 cfm with a performer rpm intake. Pistons are flat top cast, comp is 9.5. The Lunati voodoo 0701 (256/262, 213/[email protected], 454/475, 112lsa) is being replaced by a Herberts grind 270/280, 215/[email protected], 440/465 on a 112 lsa. The carb will be changed to a 650 thunder, and the manifolds with Schumacher headers. I dont want to change the 3.23 gears. Coan just recommended a Pro Street 11 inch 40215 with a 2500 stall, so I ordered one. Should I put a Trans Go level 2 shift kit in while its in the shop? So far 2 people have said stock is fine "dont mess with it" and 2 said the firmer shifts are worth it and I tend to agree. I also bought a Bouchillion performance kick down cable. Thanks in advance, guys!