Stop in for a cup of coffee

Yeah, way too hot for a 2500 stall when the engine is tuned properly with the exhaust you added. I'd pick a 3500-3800 converter to get the most out of it and add a tranny cooler to keep it in that range. I wouldn't go below 3400 nor above 3900. One could still get too tight and the other will be too loose until it's hot.
A good plan.