How did you pick your torque converter?

I agree, run a stock converter until you get your car modifications like engine, cam, tires, rear end ratio done, then buy the right converter once. Get your car and engine build sorted out and its intended purpose of usage first.

If you are not doing much drag racing then I would mention that to the converter company. You definitely want your converter "locked" when your torque curve starts coming in for highway and cruising so the car is not a dog at part throttle.

I made the mistake of buying a higher stall when I went thru the trans, with the "intention" of rebuilding the engine with big ported heads, 2.5 - 6K cam shafts, open exhaust. Then I just never did. I drove the vehicle with a loose converter and stock engine and it took all the torque out of the lower rpm range of the engine and made the vehicle very sluggish.