I'd wait until she has the money, and you feel like, swapping in a converter that will be much better matched to the engine. I have a smaller cam, and 342's as well, but trap at 6000...I'd guess mainly due to the PI 3600 stall converter making the engine rev quicker and getting the tank moving down the track quicker...
373's from 342's is not really worth the effort IMHO...If I ever swap mine, which I doubt I will, it will be to 390's or 410's, so the car will trap alot closer to it's 6700+ shift rpm.
Is a 12.0 really that much better than a 12.1?