new converter?

I rarely install anything higher than 22-2500 on a car you have to drive a lot. You can pay more for something that stalls low, but flashes higher, but it doesn't sound like you want or need that. So I'd stay lower. My rule of thumb is you want to have the engine above the flash stall (always higher than brake stall) if you're in 3rd (or OD) at 50mph. Normally that means less than 2500.
If it was me, I'd stay away from TCI. They do suck. Dead camel balls.